ClearCase: Make sure m_cmbActivity is initialized

Make sure m_cmbActivity is initialized, even when bombing out via
the QTC_ASSERT at the top of the constructor. This will fix a
coverity warning.

Change-Id: Ib5a68d8f5516ccee71c4dabc9c216092dd9c025a
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/clearcase/activityselector.h

@@ -54,9 +54,9 @@ public:
 private:
     void userChanged();
 
-    ClearCasePlugin *m_plugin;
+    ClearCasePlugin *m_plugin = nullptr;
     bool m_changed = false;
-    QComboBox *m_cmbActivity;
+    QComboBox *m_cmbActivity = nullptr;
 };
 
 } // namespace Internal