Valgrind: Remove factories from object pool when destroying them

Otherwise we get crashes on exit.

Change-Id: I806f374ba8f835c9e4361599aa901cfc4b2f0720
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/valgrind/callgrindtool.cpp

@@ -1014,7 +1014,7 @@ void initCallgrindTool()
 
 void destroyCallgrindTool()
 {
-    ExtensionSystem::PluginManager::addObject(theCallgrindRunControlFactory);
+    ExtensionSystem::PluginManager::removeObject(theCallgrindRunControlFactory);
     delete theCallgrindRunControlFactory;
     theCallgrindRunControlFactory = 0;
 }

src/plugins/valgrind/memchecktool.cpp

@@ -728,7 +728,7 @@ void initMemcheckTool()
 
 void destroyMemcheckTool()
 {
-    ExtensionSystem::PluginManager::addObject(theMemcheckRunControlFactory);
+    ExtensionSystem::PluginManager::removeObject(theMemcheckRunControlFactory);
     delete theMemcheckRunControlFactory;
     theMemcheckRunControlFactory = 0;
 }