acer-wmi: allow 64-bits return buffer from WMI methods

Acer WMID_GUID1/2 method's return buffer was declared to 64-bits
on some Acer notebook, but WMI method only use 32-bits in return
buffer.
So, add this patch for allow 64-bits return buffer.

Reference: bko#34142
	https://bugzilla.kernel.org/show_bug.cgi?id=34142

Tested on Acer Travelmate 5735Z-452G32Mnss

Tested-by: Melchior FRANZ <melchior.franz@gmail.com>
Cc: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lee, Chun-Yi <jlee@novell.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/acer-wmi.c

@@ -750,7 +750,8 @@ WMI_execute_u32(u32 method_id, u32 in, u32 *out)
 
 	obj = (union acpi_object *) result.pointer;
 	if (obj && obj->type == ACPI_TYPE_BUFFER &&
-		obj->buffer.length == sizeof(u32)) {
+		(obj->buffer.length == sizeof(u32) ||
+		obj->buffer.length == sizeof(u64))) {
 		tmp = *((u32 *) obj->buffer.pointer);
 	} else {
 		tmp = 0;
@@ -879,7 +880,8 @@ static acpi_status WMID_set_capabilities(void)
 
 	obj = (union acpi_object *) out.pointer;
 	if (obj && obj->type == ACPI_TYPE_BUFFER &&
-		obj->buffer.length == sizeof(u32)) {
+		(obj->buffer.length == sizeof(u32) ||
+		obj->buffer.length == sizeof(u64))) {
 		devices = *((u32 *) obj->buffer.pointer);
 	} else {
 		kfree(out.pointer);
@@ -1522,7 +1524,8 @@ static u32 get_wmid_devices(void)
 
 	obj = (union acpi_object *) out.pointer;
 	if (obj && obj->type == ACPI_TYPE_BUFFER &&
-		obj->buffer.length == sizeof(u32)) {
+		(obj->buffer.length == sizeof(u32) ||
+		obj->buffer.length == sizeof(u64))) {
 		devices = *((u32 *) obj->buffer.pointer);
 	}