Bluetooth: Clean up socket locking in l2cap_sock_recvmsg

This patch cleans up the locking login in l2cap_sock_recvmsg by pairing
up each lock_sock call with a release_sock call. The function already
has a "done" label that handles releasing the socket and returning from
the function so the fix is rather simple.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/l2cap_sock.c

@@ -805,8 +805,8 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 		pi->chan->state = BT_CONFIG;
 
 		__l2cap_connect_rsp_defer(pi->chan);
-		release_sock(sk);
-		return 0;
+		err = 0;
+		goto done;
 	}
 
 	release_sock(sk);