Fix NULL dereference in umem.c

Fix NULL dereference in umem.c

Signed-off-by: Neil Brown <neilb@suse.de>
Tested-by: Dave Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed