torture: Eliminate jitter_pids file

Now that there is a reliable way to convince the jitter.sh scripts to
stop, the jitter_pids file is not needed, nor is the code that kills all
the PIDs contained in this file.  This commit therefore eliminates this
file and the code using it.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh

@@ -270,20 +270,6 @@ do
 				echo "ps -fp $killpid" >> $resdir/Warnings 2>&1
 				ps -fp $killpid >> $resdir/Warnings 2>&1
 			fi
-			# Reduce probability of PID reuse by allowing a one-minute buffer
-			if test $((kruntime + 60)) -lt $seconds && test -s "$resdir/../jitter_pids"
-			then
-				awk < "$resdir/../jitter_pids" '
-				NF > 0 {
-					pidlist = pidlist " " $1;
-					n++;
-				}
-				END {
-					if (n > 0) {
-						print "kill " pidlist;
-					}
-				}' | sh
-			fi
 		else
 			echo ' ---' `date`: "Kernel done"
 		fi

tools/testing/selftests/rcutorture/bin/kvm.sh

@@ -502,12 +502,9 @@ function dump(first, pastlast, batchnum)
 	print "if test -n \"$needqemurun\""
 	print "then"
 	print "\techo ---- Starting kernels. `date` | tee -a " rd "log";
-	print "\techo > " rd "jitter_pids"
 	print "\ttouch " rd "jittering"
-	for (j = 0; j < njitter; j++) {
+	for (j = 0; j < njitter; j++)
 		print "\tjitter.sh " j " " dur " " rd "jittering " ja[2] " " ja[3] "&"
-		print "\techo $! >> " rd "jitter_pids"
-	}
 	print "\twhile ls $runfiles > /dev/null 2>&1"
 	print "\tdo"
 	print "\t\t:"