some currently unused sanity test routines for later.
count needs to be at least 1, to prevent malloc(0)
Avoid division by zero
Avoid potential malloc(0) when no syscalls match group.

Right now this shouldn't be possible, but this sanity check
will be useful when I start adding additional groups.
fix leak
when child logging fails, set all logfiles to the main logfile.
check read() return value
remove unnecessary assignment.
unnecessary assignment
Do not disable sendfile() on ENOSYS

Noticed that sendfile() was getting inactivated due to returning ENOSYS when
passed some suitable arguments:

[pid  3615] sendfile(304<socket:[73572]>, 622</sys/kernel/slab/:t-0000096/alloc_calls>, [5], 4096) = -1 ENOSYS (Function not implemented)