xdp-trafficgen: Fix exiting after completion of packet send loop

The runners_exited boolean no longer causes the event loop to exit, so
xdp-trafficgen will no longer exit if instructed to send a fixed number
of packets, after the porting to util/xdp_sample. Instead of setting the
boolean, have the packet sender thread send a SIGINT to itself after
exiting, which will cause the signal handler in xdp_sample to exit.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

Author: tohojo

xdp-trafficgen/xdp-trafficgen.c

@@ -53,7 +53,6 @@ static int mask = SAMPLE_DEVMAP_XMIT_CNT_MULTI | SAMPLE_DROP_OK;
 DEFINE_SAMPLE_INIT(xdp_trafficgen);
 
 static bool status_exited = false;
-static bool runners_exited = false;
 
 struct udp_packet {
 	struct ethhdr eth;
@@ -132,7 +131,7 @@ static void *run_traffic(void *arg)
 	if (err)
 		pr_warn("Couldn't run trafficgen program: %s\n", strerror(-err));
 
-	runners_exited = true;
+	kill(getpid(), SIGINT);
 	return NULL;
 }