arping: Fix unsolicited ARP regressions on -c > 1

4db1de6 tried to fix a regression 1 sec delay due poll() for unsolicited
ARP, .i.e. -A and -U (introduced in 67e070d, reported as issue iputils#536).
But skipping the while loop entirely introduced another regression for
-A and -U, which behave like -c1 (sending *always* only a single packet).

Fixing it by checking in while loop and comparing also count (as it was
done in 67e070d before the rewrite).

NOTE: use exit_loop with continue instead of simple break to keep things
consistent.

Fixes: 4db1de6 ("arping: Fix 1s delay on exit for unsolicited arpings")
Fixes: 67e070d ("arping: use signalfd() and timerfd() rather than signals")
Fixes: iputils#536
Closes: iputils#543
Reported-by: David Bond <[email protected]>
Reviewed-by: Andrea Cervesato <[email protected]>
Reviewed-by: Cyril Hrubis <[email protected]>
Signed-off-by: Petr Vorel <[email protected]>

arping.c

@@ -776,10 +776,15 @@ static int event_loop(struct run_state *ctl)
 	pfds[POLLFD_SOCKET].events = POLLIN | POLLERR | POLLHUP;
 	send_pack(ctl);
 
-	while (!(exit_loop || ctl->unsolicited)) {
+	while (!exit_loop) {
 		int ret;
 		size_t i;
 
+		if ((ctl->sent == ctl->count) && ctl->unsolicited) {
+			exit_loop = 1;
+			continue;
+		}
+
 		ret = poll(pfds, POLLFD_COUNT, -1);
 		if (ret <= 0) {
 			if (errno == EAGAIN)
@@ -840,6 +845,7 @@ static int event_loop(struct run_state *ctl)
 			}
 		}
 	}
+
 	close(sfd);
 	close(tfd);
 	freeifaddrs(ctl->ifa0);