window.c: Set focus widget before calling enter handler

This way input_get_focus_widget() returns the right widget when
called from the enter handler.
diff --git a/clients/window.c b/clients/window.c
index e27f3d3..314e5e9 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -1725,10 +1725,10 @@
 		widget = focus;
 		if (input->grab)
 			widget = input->grab;
+		input->focus_widget = focus;
 		if (widget->enter_handler)
 			pointer = widget->enter_handler(focus, input, x, y,
 							widget->user_data);
-		input->focus_widget = focus;
 
 		input_set_pointer_image(input, pointer);
 	}