ipifc.c: add explicit return type
 [rsc] --rw-rw-r-- M 1276246 glenda sys 34259 Mar 27 07:41 sys/src/9/ip/ipifc.c
	/n/sourcesdump/2006/0327/plan9/sys/src/9/ip/ipifc.c:831,836 - 
	/n/sourcesdump/2006/0328/plan9/sys/src/9/ip/ipifc.c:831,837
	  	return "unsupported ctl";
	  }
	  
	+ int
	  ipifcstats(Proto *ipifc, char *buf, int len)
	  {
	  	return ipstats(ipifc->f, buf, len);