weston-launch: show when a signal is sent to a child

In verbose mode, print when a signal is sent to the child process.

Signed-off-by: Stefan Agner <stefan@agner.ch>

libweston/weston-launch.c

@@ -510,7 +510,13 @@ handle_signal(struct weston_launch *wl)
 		break;
 	case SIGTERM:
 	case SIGINT:
-		if (wl->child)
+		if (!wl->child)
+			break;
+
+		if (wl->verbose)
+			fprintf(stderr, "weston-launch: sending %s to pid %d\n",
+				strsignal(sig.ssi_signo), wl->child);
+
 		kill(wl->child, sig.ssi_signo);
 		break;
 	case SIGUSR1: