Refactor redundant pattern color assignment

Instead of creating a new QColor for each condition just use the
`setRgb` method or fix the conditions order.

src/gui/AutomationPatternView.cpp

@@ -267,7 +267,7 @@ void AutomationPatternView::paintEvent( QPaintEvent * )
 
 	if( isSelected() == true )
 	{
-		c = QColor( qMax( c.red() - 128, 0 ), qMax( c.green() - 128, 0 ), 255 );
+		c.setRgb( qMax( c.red() - 128, 0 ), qMax( c.green() - 128, 0 ), 255 );
 	}
 
 	lingrad.setColorAt( 1, c.darker( 300 ) );