[PATCH] selinux: kfree cleanup

kfree(NULL) is legal.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>