inet_sendto: correct error messages and remove the comment

Comment information and printing do not match the actual function.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

net/inet/inet_sockif.c

@@ -1823,11 +1823,9 @@ static ssize_t inet_sendto(FAR struct socket *psock, FAR const void *buf,
     }
 
 #ifdef CONFIG_NET_UDP
-  /* If this is a connected socket, then return EISCONN */
-
   if (psock->s_type != SOCK_DGRAM)
     {
-      nerr("ERROR: Connected socket\n");
+      nerr("ERROR: Inappropriate socket type %d\n", psock->s_type);
       return -EBADF;
     }