shill: Add C++11 override specifier to destructors of derived classes.

BUG=None
TEST=`USE=wimax FEATURES=test emerge-$BOARD platform2`

Change-Id: I88d4e29165869b26924cccb94ac940dc8961c312
Reviewed-on: https://chromium-review.googlesource.com/212267
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
diff --git a/mock_supplicant_eap_state_handler.h b/mock_supplicant_eap_state_handler.h
index ed417e5..d05b665 100644
--- a/mock_supplicant_eap_state_handler.h
+++ b/mock_supplicant_eap_state_handler.h
@@ -16,7 +16,7 @@
 class MockSupplicantEAPStateHandler : public SupplicantEAPStateHandler {
  public:
   MockSupplicantEAPStateHandler();
-  virtual ~MockSupplicantEAPStateHandler();
+  ~MockSupplicantEAPStateHandler() override;
 
   MOCK_METHOD3(ParseStatus, bool(const std::string &status,
                                  const std::string &parameter,