Bluetooth: Fix error return value on sendmsg.

When we try to send a message bigger than the outgoing MTU value
EMSGSIZE (message too long) should be returned.
Signed-off-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap.c

@@ -1827,7 +1827,7 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
 	case L2CAP_MODE_BASIC:
 		/* Check outgoing MTU */
 		if (len > pi->omtu) {
-			err = -EINVAL;
+			err = -EMSGSIZE;
 			goto done;
 		}