Bluetooth: Fix double error response for l2cap_create_chan_req

When an L2CAP request handler returns non-zero the calling code will
send a command reject response. The l2cap_create_chan_req function will
in some cases send its own response but then still return a -EFAULT
error which would cause two responses to be sent. This patch fixes this
by making the function return 0 after sending its own response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/l2cap_core.c

@@ -4462,7 +4462,7 @@ static int l2cap_create_channel_req(struct l2cap_conn *conn,
 	l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
 		       sizeof(rsp), &rsp);
 
-	return -EFAULT;
+	return 0;
 }
 
 static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)