psm: calloc the size that is needed

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
Merge pull request #405 from jsquyres/pr/psm-voidstar-deref

psm: calloc the size that is needed
Brought usnic_direct update-to-date

Signed-off-by: Xuyang Wang <xuywang@cisco.com>