#28 check_snmp: 127 char truncation bug

[Alexander Haderer]

The vsnprintf() function used in plugins/utils.c has platform specific return codes
if the output string is longer than the given size (128 defined in TXTBLK).
The code in utils.c only works on linuxoid systems where vsnprintf returns
-1 if the output string is to long. BSDish systems return the size that
would have been output, the builtin version of vsnprintf returns 127 if the
output is to long. As a result all output longer than 127 chars will be truncated
to 127 chars on non linux systems.

plugins concerned (at least): check_snmp

The patch supplied fixes this bug for check_snmp and all other programs that
use the vsnprintf function as well.

[Alexander Haderer]

patch for plugins/utils.c (diff -U 3 oldfile newfile)