wbemprox/tests: Fix a memory leak (Valgrind).

Signed-off-by: Sven Baars <sven.wine@gmail.com>
Signed-off-by: Hans Leidekker <hans@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/wbemprox/tests/query.c

@@ -1654,6 +1654,7 @@ static void test_Win32_PnPEntity( IWbemServices *services )
                 VariantClear( &val );
             }
         }
+        IWbemClassObject_Release( obj );
     }
 
     SysFreeString( bstr );