udhcpc: remove code which requires server ID to be on local network

This reverts "udhcpc: paranoia when using kernel UDP mode
for sending renew: server ID may be bogus".

Users complain that they do have servers behind routers
(with DHCP relays).

function                                             old     new   delta
send_packet                                          168     166      -2
bcast_or_ucast                                        25      23      -2
udhcp_send_kernel_packet                             301     295      -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-10)             Total: -10 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index c206a58..c2805a0 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -693,16 +693,10 @@
 
 static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server)
 {
-	if (server) {
-		/* Without MSG_DONTROUTE, the packet was seen routed over
-		 * _other interface_ if server ID is bogus (example: 1.1.1.1).
-		 */
+	if (server)
 		return udhcp_send_kernel_packet(packet,
 			ciaddr, CLIENT_PORT,
-			server, SERVER_PORT,
-			/*send_flags: "to hosts only on directly connected networks" */ MSG_DONTROUTE
-		);
-	}
+			server, SERVER_PORT);
 	return raw_bcast_from_client_config_ifindex(packet, ciaddr);
 }