[PATCH] reiserfs: fix potential (unlikely) oops in reiserfs_get_acl

This fixes a potential oops if there is an error reported by
posix_acl_from_disk().  This is mostly theoretical due to the use of
magics and checksums in xattrs, but is still possible.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>