inspector: Check a return value

We don't care about the error here, but we were relying on
g_resources_get_info to zero the size even in case of error.
No need to do that, we can just check the return value. Plus,
it makes coverity happy.

gtk/inspector/resource-list.c

@@ -95,7 +95,8 @@ load_resources_recurse (GtkInspectorResourceList *sl,
       else
         {
           count = 1;
-          g_resources_get_info (p, 0, &size, NULL, NULL);
+          if (!g_resources_get_info (p, 0, &size, NULL, NULL))
+            size = 0;
         }
 
       stored_size = size;