replace acpi_util_eval_error macro with static function.

Avoid these sparse warnings due to using buffer within the macro.
drivers/acpi/utils.c:273:3: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:259:21: originally declared here
drivers/acpi/utils.c:279:3: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:259:21: originally declared here
drivers/acpi/utils.c:368:3: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:348:21: originally declared here
drivers/acpi/utils.c:375:3: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:348:21: originally declared here
drivers/acpi/utils.c:382:3: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:348:21: originally declared here
drivers/acpi/utils.c:402:4: warning: symbol 'buffer' shadows an earlier one
drivers/acpi/utils.c:348:21: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>