clients: Add delete handler for simple-shm / simple-egl

It seems this was forgotten in the port.
diff --git a/clients/simple-shm.c b/clients/simple-shm.c
index 2dbe7cb..ec130ed 100644
--- a/clients/simple-shm.c
+++ b/clients/simple-shm.c
@@ -61,6 +61,8 @@
 	struct wl_callback *callback;
 };
 
+static int running = 1;
+
 static void
 buffer_release(void *data, struct wl_buffer *buffer)
 {
@@ -147,6 +149,12 @@
 {
 }
 
+static void
+handle_delete(void *data, struct xdg_surface *xdg_surface)
+{
+	running = 0;
+}
+
 static const struct xdg_surface_listener xdg_surface_listener = {
 	handle_configure,
 	handle_request_set_maximized,
@@ -155,6 +163,7 @@
 	handle_request_unset_fullscreen,
 	handle_focused_set,
 	handle_focused_unset,
+	handle_delete,
 };
 
 static struct window *
@@ -423,8 +432,6 @@
 	free(display);
 }
 
-static int running = 1;
-
 static void
 signal_int(int signum)
 {