isdn: gigaset: add missing unlock

We should unlock here.  This is the only place where we return from the
function with the lock held.  The caller isn't expecting it.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/gigaset/capi.c

@@ -1052,6 +1052,7 @@ static inline void remove_appl_from_channel(struct bc_state *bcs,
 	do {
 		if (bcap->bcnext == ap) {
 			bcap->bcnext = bcap->bcnext->bcnext;
+			spin_unlock_irqrestore(&bcs->aplock, flags);
 			return;
 		}
 		bcap = bcap->bcnext;