Fix parent to avoid setGeometry warnings on Qt5

Author: vallsv

silx/gui/plot/PlotWindow.py

@@ -32,7 +32,7 @@
 
 __authors__ = ["V.A. Sole", "T. Vincent"]
 __license__ = "MIT"
-__date__ = "05/10/2016"
+__date__ = "10/10/2016"
 
 import collections
 import logging
@@ -167,11 +167,11 @@ def __init__(self, parent=None, backend=None,
         self.colormapAction.setVisible(colormap)
 
         self.keepDataAspectRatioButton = PlotToolButtons.AspectToolButton(
-            parent=None, plot=self)
+            parent=self, plot=self)
         self.keepDataAspectRatioButton.setVisible(aspectRatio)
 
         self.yAxisInvertedButton = PlotToolButtons.YAxisOriginToolButton(
-            parent=None, plot=self)
+            parent=self, plot=self)
         self.yAxisInvertedButton.setVisible(yInverted)
 
         self.group.addAction(self.roiAction)