if there are no rx packets when is called (and while it
waits 100ms), etherrxflush will give the head of the rx queue back
to the interface but the interface doesn't know that, so the queue
will be jamed, thus causing bootp to fail.

Notes:
Wed Sep 19 19:14:15 EDT 2007 geoff
    deferred.


Reference: /n/sources/patch/saved/9load-bootp
Date: Sat Jun 16 14:08:59 CES 2007
Signed-off-by: quanstro@quanstro.net
Reviewed-by: geoff

--- /sys/src/boot/pc/bootp.c	Sat Jun 16 14:06:11 2007
+++ /sys/src/boot/pc/bootp.c	Sat Jun 16 14:06:06 2007
@@ -472,7 +472,7 @@
 	myaddr.port = BPportsrc;
 	memmove(myaddr.ea, ea, Eaddrlen);
 
-	etherrxflush(ctlrno);
+//	etherrxflush(ctlrno);
 	for(i = 0; i < 10; i++) {
 		server.ip = Bcastip;
 		server.port = BPportdst;