analyzer: fix performance problem when resorting valgrind views

Task-number: QTCREATORBUG-6319
Change-Id: I5a2cc1845104bb16f912fe258ba25473ba85cefd
Reviewed-by: hjk <qthjk@ovi.com>
(cherry picked from commit b3ae7d7e)

src/plugins/valgrind/callgrindcostview.cpp

@@ -71,6 +71,7 @@ CostView::CostView(QWidget *parent)
     setSelectionBehavior(QAbstractItemView::SelectRows);
     setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
     setHorizontalScrollMode(QAbstractItemView::ScrollPerPixel);
+    setUniformRowHeights(true);
     setAutoScroll(false);
     setSortingEnabled(true);
     setRootIsDecorated(false);