nisplus: Fix leak on realloc failure in nis_getnames
nisplus: Fix leak on realloc failure in nis_getnames

If pos >= count but realloc fails, tmp will not have been placed in
getnames[pos] yet, and so will not be freed in free_null.  Detected
by Coveriy.

Also remove misleading comment from nis_getnames(), since it actually
did properly release getnames when out of memory.

Corresponds to glibc commit 60698263122b7c54ded3f70a466176e17a529480

Signed-off-by: Robbie Harwood <3f8631879978f4cea53bf1163760f1ac18f9cb08@redhat.com>

thkukuk/libnsl,thkukuk/libnsl,thkukuk/libnsl