Prevent double logging of some ALTER <object> SET SCHEMA statements

Some ALTER <object> SET SCHEMA statements will be handled by the object
access hook in 9.3 and 9.4
Prevent "unused function" warning

This warning:

    ‘log_create_or_alter’ defined but not used [-Wunused-function]

occurs because log_create_or_alter() will never be called if
USE_DEPARSE_FUNCTIONS is defined.