ACPI / tables: Return proper error codes from acpi_table_parse() and fix comment.

The comment about return value of acpi_table_parse() is incorrect.
This patch fix it.

Since all callers only check if the function succeeded or not, this
patch simplifies the semantics by returning -errno for all failure
cases. This will also simply the comment.

As suggested by Toshi Kani <toshi.kani@hp.com>, also change the stub
in linux/acpi.h to return -ENODEV.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/tables.c

@@ -278,12 +278,13 @@ acpi_table_parse_madt(enum acpi_madt_type id,
 
 /**
  * acpi_table_parse - find table with @id, run @handler on it
- *
  * @id: table id to find
  * @handler: handler to run
  *
  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
- * run @handler on it.  Return 0 if table found, return on if not.
+ * run @handler on it.
+ *
+ * Return 0 if table found, -errno if not.
  */
 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
 {

include/linux/acpi.h

@@ -461,7 +461,7 @@ struct acpi_table_header;
 static inline int acpi_table_parse(char *id,
 				int (*handler)(struct acpi_table_header *))
 {
-	return -1;
+	return -ENODEV;
 }
 
 static inline int acpi_nvs_register(__u64 start, __u64 size)