net: ipv6: fix wrong ping_v6_sendmsg return value

ping_v6_sendmsg currently returns 0 on success. It should return
the number of bytes written instead.
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ping.c

@@ -191,7 +191,10 @@ int ping_v6_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	}
 	release_sock(sk);
 
-	return err;
+	if (err)
+		return err;
+
+	return len;
 }
 
 #ifdef CONFIG_PROC_FS