arping: Optimize loop checking

4db1de6 introduced regression for -A and -U, which behave like -c1
(.i.e. sending only single packet). Fixing it to compare also count
(as it was done in 67e070d before the rewrite).

But it keeps 1 sec delay due poll() for -c > 1 (more than a single
packet), e.g. 67e070d is not fixed.

Also, ctl->unsolicited does not change, therefore it's enough be checked
only once (before while loop).

Fixes: 4db1de6 ("arping: Fix 1s delay on exit for unsolicited arpings")
Reported-by: David Bond <dbond@suse.com>
Signed-off-by: Petr Vorel <pvorel@suse.cz>

arping.c

@@ -776,7 +776,10 @@ static int event_loop(struct run_state *ctl)
 	pfds[POLLFD_SOCKET].events = POLLIN | POLLERR | POLLHUP;
 	send_pack(ctl);
 
-	while (!(exit_loop || ctl->unsolicited)) {
+	if ((ctl->sent == ctl->count) && ctl->unsolicited)
+		goto exit;
+
+	while (!exit_loop) {
 		int ret;
 		size_t i;
 
@@ -840,6 +843,7 @@ static int event_loop(struct run_state *ctl)
 			}
 		}
 	}
+exit:
 	close(sfd);
 	close(tfd);
 	freeifaddrs(ctl->ifa0);