Remove debugging print.
 [jmk] --rw-rw-r-- M 23749 glenda sys 5589 Jan 31 11:12 sys/src/cmd/ip/ping.c
	/n/sourcesdump/2006/0131/plan9/sys/src/cmd/ip/ping.c:185,191 - 
	/n/sourcesdump/2006/0201/plan9/sys/src/cmd/ip/ping.c:185,190
	  		alarm(0);
	  		now = nsec();
	  		if(n <= 0){	/* read interrupted - time to go */
	- fprint(2, "clean\n");
	  			clean(0, now+MINUTE, nil);
	  			continue;
	  		}