fixes ChannelSlider::Draw when Label() is NULL

fixes a bit preferred size, still needs work


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16212 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/ChannelControl.cpp

@@ -168,12 +168,17 @@ BChannelControl::DetachedFromWindow()
 }
 
 
+void
+BChannelControl::GetPreferredSize(float *_width, float *_height)
+{
+	BControl::GetPreferredSize(_width, _height);
+}
+
+
 void
 BChannelControl::ResizeToPreferred()
 {
-	float width, height;
-	GetPreferredSize(&width, &height);
-	ResizeTo(width, height);
+	BControl::ResizeToPreferred();
 }