swaybg: make argv const

swaybg/main.c

@@ -23,7 +23,7 @@ void sway_terminate(void) {
 	exit(1);
 }
 
-int main(int argc, char **argv) {
+int main(int argc, const char **argv) {
 	init_log(L_INFO);
 	surfaces = create_list();
 	registry = registry_poll();
@@ -49,7 +49,7 @@ int main(int argc, char **argv) {
 	desktop_shell_set_background(registry->desktop_shell, output->output, window->surface);
 	list_add(surfaces, window);
 
-	char *scaling_mode = argv[3];
+	const char *scaling_mode = argv[3];
 	cairo_surface_t *image = cairo_image_surface_create_from_png(argv[2]);
 	double width = cairo_image_surface_get_width(image);
 	double height = cairo_image_surface_get_height(image);