fs/afs/security.c: fix uninitialized var warning

fs/afs/security.c: In function 'afs_permission':
fs/afs/security.c:290: warning: 'access' may be used uninitialized in this function

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>