Shibatch audio tools

on line 1157 of ssrc:

for(i=0;i<nch;i++) {
buf2[i] = malloc(sizeof(REAL)*(n2x+1+n1b2));
for(j=0;j<n2x+n1b2;j++) buf2[i][j] = 0;
}

buf2 is not cleared to the last sample, and that sample
is being used (later when running the filter the last
sample is buf2[][]+=buf1[] this bad sample is causing
multiple samples later on to go > 1.

To fix clear to the last sample:

for(i=0;i<nch;i++) {
buf2[i] = malloc(sizeof(REAL)*(n2x+1+n1b2));
for(j=0;j<n2x+n1b2+1;j++) buf2[i][j] = 0;
}