Don't kill() running threads

Just let them exit nicely.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.c b/fio.c
index 45ed354..f183eeb 100644
--- a/fio.c
+++ b/fio.c
@@ -67,7 +67,11 @@
 
 	for_each_td(td, i) {
 		if (group_id == TERMINATE_ALL || groupid == td->groupid) {
-			kill(td->pid, SIGQUIT);
+			/*
+			 * if the thread is running, just let it exit
+			 */
+			if (td->runstate < TD_RUNNING)
+				kill(td->pid, SIGQUIT);
 			td->terminate = 1;
 			td->start_delay = 0;
 		}