kernel: remove various wrong code
 [rsc] --rw-rw-r-- M 467740 glenda sys 22993 Mar 12 10:33 sys/src/9/port/devcons.c
	/n/sourcesdump/2006/0312/plan9/sys/src/9/port/devcons.c:397,403 - 
	/n/sourcesdump/2006/0313/plan9/sys/src/9/port/devcons.c:397,402
	  echo(char *buf, int n)
	  {
	  	static int ctrlt, pid;
	- 	extern ulong etext;
	  	int x;
	  	char *e, *p;
	  
 [rsc] --rw-rw-r-- M 467740 presotto sys 19576 Mar 12 10:33 sys/src/9/ppc/etherfcc.c
	/n/sourcesdump/2006/0312/plan9/sys/src/9/ppc/etherfcc.c:684,690 - 
	/n/sourcesdump/2006/0313/plan9/sys/src/9/ppc/etherfcc.c:684,690
	  		return -1;
	  	}
	  
	- 	if(!(ether->port >= 0 && ether->port < 3)){
	+ 	if(ether->port > 3){
	  		print("%s ether: no FCC port %ld\n", ether->type, ether->port);
	  		return -1;
	  	}