If a connection is reset while trying to talk to it slurm_get_peer_addr
will return ENOTCONN and not initialize the addr_str causing valgrind
errors.
Validate return code from calls to slurm_get_peer_addr
Have bitstring use the xmalloc stuff instead of calloc and realloc.
It was found the realloc logic could result in Valgrind complaining of
uninitialized data when doing a bit_fmt on the realloced bit structure.
using xrealloc instead fixes the issue and makes things good, perhaps
speeds things up as well.
Merge remote-tracking branch 'origin/slurm-2.6'

Conflicts:
	src/slurmctld/proc_req.c