Bluetooth: Fix another locking unbalance

l2cap_get_sock_by_scid was changed to not lock the socket anymore, but I
forgot to change all the users of this function.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index d5db5a3..bc84ed1 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -632,6 +632,8 @@
 	if (!parent)
 		return;
 
+	bh_lock_sock(parent);
+
 	/* Check for backlog size */
 	if (sk_acceptq_is_full(parent)) {
 		BT_DBG("backlog full %d", parent->sk_ack_backlog);