#256 fix final sum and write histo sum with tcp

[Robert McMahon]

[rjmcmahon@ryzen3950 iperf2-code]$ src/iperf -c mail.rjmcmahon.com --tcp-write-times --histograms=1m -P 4 --tcp-write-prefetch 128K -i 1 -t2
------------------------------------------------------------
Client connecting to mail.rjmcmahon.com, TCP port 5001 with pid 211624 (4 flows)
Write buffer size: 131072 Byte (writetimer-enabled)
TCP congestion control using cubic
TOS set to 0x0 (Nagle on)
TCP window size: 85.0 KByte (default)
Event based writes (pending queue watermark at 131072 bytes)
Enabled write histograms bin-width=1.000 ms, bins=100000
------------------------------------------------------------
[  2] local 192.168.1.69%enp4s0 port 46320 connected with 45.33.58.123 port 5001 (prefetch=131072) (sock=4) (icwnd/mss/irtt=14/1448/12355) (ct=12.39 ms) on 2023-04-18 10:31:14.952 (PDT)
[  1] local 192.168.1.69%enp4s0 port 46306 connected with 45.33.58.123 port 5001 (prefetch=131072) (sock=3) (icwnd/mss/irtt=14/1448/12402) (ct=12.48 ms) on 2023-04-18 10:31:14.952 (PDT)
[  3] local 192.168.1.69%enp4s0 port 46324 connected with 45.33.58.123 port 5001 (prefetch=131072) (sock=5) (icwnd/mss/irtt=14/1448/16793) (ct=16.83 ms) on 2023-04-18 10:31:14.952 (PDT)
[  4] local 192.168.1.69%enp4s0 port 46332 connected with 45.33.58.123 port 5001 (prefetch=131072) (sock=6) (icwnd/mss/irtt=14/1448/16683) (ct=16.74 ms) on 2023-04-18 10:31:14.952 (PDT)
[ ID] Interval        Transfer    Bandwidth       Write/Err  Rtry     Cwnd/RTT        NetPwr  write-times avg/min/max/stdev (cnt)
[  4] 0.00-1.00 sec  1.88 MBytes  15.7 Mbits/sec  15/1        147      38K/16943 us  116  69.158/20.362/108.356/32.265 ms (15)
[  4] 0.00-1.00 sec W8-PDF: bin(w=1ms):cnt(15)=21:1,25:2,39:1,41:1,58:1,75:1,77:1,81:1,89:1,93:1,101:1,105:1,106:1,109:1 (5.00/95.00/99.7%=21/109/109,Outliers=0,obl/obu=0/0)
[  3] 0.00-1.00 sec  1.50 MBytes  12.6 Mbits/sec  12/1        102      31K/16407 us  95.87  84.065/19.102/145.243/43.158 ms (12)
[  3] 0.00-1.00 sec W8-PDF: bin(w=1ms):cnt(12)=20:1,24:1,38:1,41:1,81:1,89:1,109:1,114:1,116:2,122:1,146:1 (5.00/95.00/99.7%=20/146/146,Outliers=0,obl/obu=0/0)
[  2] 0.00-1.00 sec  1.00 MBytes  8.39 Mbits/sec  8/1         63      14K/13422 us  78.13  136.474/22.206/229.248/76.395 ms (8)
[  2] 0.00-1.00 sec W8-PDF: bin(w=1ms):cnt(8)=23:1,54:1,79:1,135:1,185:1,188:1,202:1,230:1 (5.00/95.00/99.7%=23/230/230,Outliers=0,obl/obu=0/0)
[  1] 0.00-1.00 sec  1.25 MBytes  10.5 Mbits/sec  10/1         89      12K/14386 us  91.11  110.239/22.755/160.546/47.206 ms (10)
[  1] 0.00-1.00 sec W8-PDF: bin(w=1ms):cnt(10)=23:1,48:1,71:1,121:1,122:1,123:1,135:1,144:1,158:1,161:1 (5.00/95.00/99.7%=23/161/161,Outliers=0,obl/obu=0/0)
[ ID] Interval        Transfer    Bandwidth       Write/Err  Rtry     Cwnd/RTT(var)        NetPwr
[SUM] 0.00-1.00 sec  5.63 MBytes  47.2 Mbits/sec  45/4       401
[  4] 1.00-2.00 sec  1.00 MBytes  8.39 Mbits/sec  8/0          9      12K/17191 us  61.00  93.912/0.029/227.180/70.542 ms (8)
[  4] 1.00-2.00 sec W8-PDF: bin(w=1ms):cnt(8)=1:1,44:1,50:1,63:1,112:1,128:1,130:1,228:1 (5.00/95.00/99.7%=1/228/228,Outliers=0,obl/obu=0/0)
[  3] 1.00-2.00 sec  1.88 MBytes  15.7 Mbits/sec  15/0          5      31K/14867 us  132  66.485/0.028/110.137/22.307 ms (15)
[  3] 1.00-2.00 sec W8-PDF: bin(w=1ms):cnt(15)=1:1,59:1,61:1,65:2,66:2,67:1,69:1,70:2,72:1,77:1,86:1,111:1 (5.00/95.00/99.7%=1/111/111,Outliers=0,obl/obu=0/0)
[  2] 1.00-2.00 sec  1.12 MBytes  9.44 Mbits/sec  9/0          3      29K/16972 us  69.51  103.937/74.560/153.931/24.832 ms (9)
[  2] 1.00-2.00 sec W8-PDF: bin(w=1ms):cnt(9)=75:1,83:1,86:1,88:1,103:1,111:1,116:1,123:1,154:1 (5.00/95.00/99.7%=75/154/154,Outliers=0,obl/obu=0/0)
[  1] 1.00-2.00 sec   768 KBytes  6.29 Mbits/sec  6/0          5      21K/16680 us  47.15  150.811/121.820/206.539/30.948 ms (6)
[  1] 1.00-2.00 sec W8-PDF: bin(w=1ms):cnt(6)=122:1,125:1,142:1,155:1,157:1,207:1 (5.00/95.00/99.7%=122/207/207,Outliers=0,obl/obu=0/0)
[SUM] 1.00-2.00 sec  4.75 MBytes  39.8 Mbits/sec  38/0        22
[  3] 0.00-2.18 sec  3.50 MBytes  13.5 Mbits/sec  28/2        108      24K/17308 us  97.35  74.031/0.028/145.243/33.093 ms (28)
[  3] 0.00-2.18 sec W8(f)-PDF: bin(w=1ms):cnt(28)=1:1,20:1,24:1,38:1,41:1,59:1,61:1,65:2,66:2,67:2,69:1,70:2,72:1,77:1,81:1,86:1,89:1,109:1,111:1,114:1,116:2,122:1,146:1 (5.00/95.00/99.7%=20/122/146,Outliers=0,obl/obu=0/0)
[  2] 0.00-2.19 sec  2.25 MBytes  8.60 Mbits/sec  18/2         66      32K/18431 us  58.33  116.859/22.206/229.248/55.315 ms (18)
[  2] 0.00-2.19 sec W8(f)-PDF: bin(w=1ms):cnt(18)=23:1,54:1,75:1,77:1,79:1,83:1,86:1,88:1,103:1,111:1,116:1,123:1,135:1,154:1,185:1,188:1,202:1,230:1 (5.00/95.00/99.7%=23/230/230,Outliers=0,obl/obu=0/0)
[  1] 0.00-2.21 sec  2.13 MBytes  8.07 Mbits/sec  17/2         94      25K/14845 us  67.91  124.314/22.755/206.539/44.279 ms (17)
[  1] 0.00-2.21 sec W8(f)-PDF: bin(w=1ms):cnt(17)=23:1,48:1,71:1,107:1,121:1,122:2,123:1,125:1,135:1,142:1,144:1,155:1,157:1,158:1,161:1,207:1 (5.00/95.00/99.7%=23/207/207,Outliers=0,obl/obu=0/0)
[  4] 0.00-2.23 sec  3.00 MBytes  11.3 Mbits/sec  24/2        156      21K/14736 us  95.86  84.018/0.029/227.767/56.786 ms (24)
[  4] 0.00-2.23 sec W8(f)-PDF: bin(w=1ms):cnt(24)=1:1,21:1,25:2,39:1,41:1,44:1,50:1,58:1,63:1,75:1,77:1,81:1,89:1,93:1,101:1,105:1,106:1,109:1,112:1,128:1,130:1,228:2 (5.00/95.00/99.7%=21/228/228,Outliers=0,obl/obu=0/0)
[SUM] 0.00-2.11 sec  10.9 MBytes  43.2 Mbits/sec  87/8       424
[ CT] final connect times (min/avg/max) = 12.393/14.613/16.834 ms (tot/err) = 4/0