apparmor: Replace spin_is_locked() with lockdep

lockdep_assert_held() is better suited to checking locking requirements,
since it won't get confused when someone else holds the lock. This is
also a step towards possibly removing spin_is_locked().

Signed-off-by: Lance Roy <[e-mail]>
Cc: John Johansen <[e-mail]>
Cc: James Morris <[e-mail]>
Cc: "Serge E. Hallyn" <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: John Johansen <[e-mail]>

security/apparmor/file.c

···
 	/* update caching of label on file_ctx */
 	spin_lock(&fctx->lock);
 	old = rcu_dereference_protected(fctx->label,
-					spin_is_locked(&fctx->lock));
+					lockdep_is_held(&fctx->lock));
 	l = aa_label_merge(old, label, GFP_ATOMIC);
 	if (l) {
 		if (l != old) {