PixelPaint: Use image coordinates for bucket tool bounds checking

Previously, layer coordinates were being used to check whether the
bucket tool was within the bounds of the current selection, rather
than image coordinates.

Userland/Applications/PixelPaint/Tools/BucketTool.cpp

@@ -50,7 +50,7 @@ void BucketTool::on_mousedown(Layer* layer, MouseEvent& event)
     if (!layer->rect().contains(layer_event.position()))
         return;
 
-    if (auto selection = layer->image().selection(); !selection.is_empty() && !selection.is_selected(layer_event.position()))
+    if (auto selection = layer->image().selection(); !selection.is_empty() && !selection.is_selected(event.image_event().position()))
         return;
 
     GUI::Painter painter(layer->get_scratch_edited_bitmap());