cam: Fix cam --help crash

The cam utility does not terminate correctly if invoked with only
--help. It prints the help information and then segfaults due to the
application incorrectly handling the return value. Fix this by moving
the return code check of the option parsing to main().

Reported-by: Emmanuel Arias <eamanu@eamanu.com>
Suggested-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/cam/main.cpp

@@ -61,7 +61,7 @@ int CamApp::init(int argc, char **argv)
 
 	ret = parseOptions(argc, argv);
 	if (ret < 0)
-		return ret == -EINTR ? 0 : ret;
+		return ret;
 
 	cm_ = CameraManager::instance();
 
@@ -193,9 +193,11 @@ void signalHandler(int signal)
 int main(int argc, char **argv)
 {
 	CamApp app;
+	int ret;
 
-	if (app.init(argc, argv))
-		return EXIT_FAILURE;
+	ret = app.init(argc, argv);
+	if (ret)
+		return ret == -EINTR ? 0 : EXIT_FAILURE;
 
 	struct sigaction sa = {};
 	sa.sa_handler = &signalHandler;