testsuite: Clarify error

200% is not a fractional scale, but it's still forbidden.

testsuite/gsk/offload.c

@@ -391,7 +391,7 @@ parse_node_file (GFile *file, const char *generate)
 
   if (gdk_surface_get_scale (surface) != 1.0)
     {
-      g_print ("Offload tests don't work with fractional scales\n");
+      g_print ("Offload tests don't work with scale != 1.0\n");
       exit (77);
     }