Revert "net/ieee802154: reject zero-sized raw_sendmsg()"

This reverts commit 3a4d061c.

There is a v2 which does return zero if zero length is given.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20221005014750.3685555-1-aahringo@redhat.comSigned-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

net/ieee802154/socket.c

@@ -251,9 +251,6 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 		return -EOPNOTSUPP;
 	}
 
-	if (!size)
-		return -EINVAL;
-
 	lock_sock(sk);
 	if (!sk->sk_bound_dev_if)
 		dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);