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>
diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
index e5ea344..bcc174e 100644
--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -1052,6 +1052,7 @@
 	do {
 		if (bcap->bcnext == ap) {
 			bcap->bcnext = bcap->bcnext->bcnext;
+			spin_unlock_irqrestore(&bcs->aplock, flags);
 			return;
 		}
 		bcap = bcap->bcnext;