Add missing override keyword on mock

This mock method is missing an override keyword.  Looks like an
unintentional omission.  Add it.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Ia1c2ee09ddbb5add0485b2e3f66347823bf959af
diff --git a/include/sdbusplus/test/sdbus_mock.hpp b/include/sdbusplus/test/sdbus_mock.hpp
index 5f419b9..c61fe1c 100644
--- a/include/sdbusplus/test/sdbus_mock.hpp
+++ b/include/sdbusplus/test/sdbus_mock.hpp
@@ -126,7 +126,8 @@
     MOCK_METHOD(int, sd_bus_message_open_container,
                 (sd_bus_message*, char, const char*), (override));
 
-    MOCK_METHOD(int, sd_bus_message_read_basic, (sd_bus_message*, char, void*));
+    MOCK_METHOD(int, sd_bus_message_read_basic, (sd_bus_message*, char, void*),
+                (override));
     MOCK_METHOD(sd_bus_message*, sd_bus_message_ref, (sd_bus_message*),
                 (override));