Cleanup memory owned by QTestTablePrivate

Since 7a42c8c15c QTestTablePrivate no
longer cleans up the memory it holds in dataList. This will make tools
such as valgrind/address-sanitizer generate a lot of noise about
directly or indirectly leaked memory.

Change-Id: Ic0900ecdd7b76cda9f5366f3950bccde2f1b244c
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@theqtcompany.com>

src/testlib/qtesttable.cpp

@@ -46,6 +46,11 @@ QT_BEGIN_NAMESPACE
 class QTestTablePrivate
 {
 public:
+    ~QTestTablePrivate()
+    {
+        qDeleteAll(dataList.begin(), dataList.end());
+    }
+
     struct Element {
         Element() : name(Q_NULLPTR), type(0) {}
         Element(const char *n, int t) : name(n), type(t) {}