ACPICA: macros: fix ACPI_ERROR_NAMESPACE macro

Fixing the ACPI_ERROR_NAMESPACE macros created an "unused variable"
compile error when ACPI_NO_ERROR_MESSAGES was defined. This commit
also fixes the above compilation errors by surrounding variables
meant for debugging inside a new ACPI_ERROR_ONLY macro.

Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>