userns: Convert loop to use kuid_t instead of uid_t

Cc: Jens Axboe <jaxboe@fusionio.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

drivers/block/loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3bba655..e9d594f 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1038,10 +1038,10 @@
 {
 	int err;
 	struct loop_func_table *xfer;
-	uid_t uid = current_uid();
+	kuid_t uid = current_uid();
 
 	if (lo->lo_encrypt_key_size &&
-	    lo->lo_key_owner != uid &&
+	    !uid_eq(lo->lo_key_owner, uid) &&
 	    !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (lo->lo_state != Lo_bound)