Fixed issue when auto-showing toolbar in fullscreen mode.

If you've zoomed in fullscreen mode and moved the mouse to the top of the
screen, the toolbar didn't appear. You had to scroll up to the top of zoomed
image first. Using the screen coords instead of the view coords fixes this.

src/apps/showimage/ShowImageView.cpp

@@ -1172,7 +1172,7 @@ ShowImageView::MouseMoved(BPoint point, uint32 state, const BMessage* message)
 	fHideCursorCountDown = HIDE_CURSOR_DELAY_TIME;
 	if (fHideCursor) {
 		// Show toolbar when mouse hits top 15 pixels, hide otherwise
-		_ShowToolBarIfEnabled(point.y <= 15);
+		_ShowToolBarIfEnabled(ConvertToScreen(point).y <= 15);
 	}
 	if (fCreatingSelection)
 		_UpdateSelectionRect(point, false);