Make it compile again after latest patches.

Reference: /n/patches.lsub.org/patch/ipcompile
Date: Fri Jul 20 11:00:44 CES 2012
Signed-off-by: paurea@lsub.org

--- /sys/src/nix/ip/tcp.c	Thu Jul 19 10:14:16 2012
+++ /sys/src/nix/ip/tcp.c	Fri Jul 20 10:04:23 2012
@@ -791,12 +791,12 @@
 	case V4:
 		mtu = DEF_MSS;
 		if(ifc != nil)
-			mtu = ifc->maxtu - ifc->m->hsize - (TCP4_PKT + TCP4_HDRSIZE);
+			mtu = ifc->maxtu - ifc->medium->hsize - (TCP4_PKT + TCP4_HDRSIZE);
 		break;
 	case V6:
 		mtu = DEF_MSS6;
 		if(ifc != nil)
-			mtu = ifc->maxtu - ifc->m->hsize - (TCP6_PKT + TCP6_HDRSIZE);
+			mtu = ifc->maxtu - ifc->medium->hsize - (TCP6_PKT + TCP6_HDRSIZE);
 		break;
 	}
 	if(ifc != nil){
--- /sys/src/nix/ip/udp.c	Thu Jul 19 10:12:48 2012
+++ /sys/src/nix/ip/udp.c	Fri Jul 20 10:07:20 2012
@@ -416,7 +416,7 @@
 			icmpnoconv(f, bp);
 			break;
 		case V6:
-			icmphostunr(f, ifc, bp, Icmp6_port_unreach, 0);
+			icmphostunr(f, ifc, bp, icmp6_adr_unreach, 0);
 			break;
 		default:
 			panic("udpiput2: version %d", version);