ACPI: check acpi_disabled in acpi_table_parse() and acpi_table_parse_entries()

Allow consumers of the acpi_table_parse()/acpi_table_parse_entries() API
to gracefully handle the acpi_disabled=1 case via return value
rather than checking the global flag themselves.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/tables.c

@@ -213,6 +213,9 @@ acpi_table_parse_entries(char *id,
 	unsigned long table_end;
 	acpi_size tbl_size;
 
+	if (acpi_disabled)
+		return -ENODEV;
+
 	if (!handler)
 		return -EINVAL;
 
@@ -277,6 +280,9 @@ int __init acpi_table_parse(char *id, acpi_table_handler handler)
 	struct acpi_table_header *table = NULL;
 	acpi_size tbl_size;
 
+	if (acpi_disabled)
+		return -ENODEV;
+
 	if (!handler)
 		return -EINVAL;