asus-wmi: use ASUS_WMI_METHODID_DSTS2 as default DSTS ID.

According to responses from the BIOS team, ASUS_WMI_METHODID_DSTS2
(0x53545344) will be used as future DSTS ID. In addition, calling
asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS2, 0, 0, NULL) returns
ASUS_WMI_UNSUPPORTED_METHOD in new ASUS laptop PCs. This patch fixes
no DSTS ID will be assigned in this case.

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@kernel.org
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 77aadde..556cbb4 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1467,14 +1467,9 @@
 	 */
 	if (!asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS, 0, 0, NULL))
 		asus->dsts_id = ASUS_WMI_METHODID_DSTS;
-	else if (!asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS2, 0, 0, NULL))
+	else
 		asus->dsts_id = ASUS_WMI_METHODID_DSTS2;
 
-	if (!asus->dsts_id) {
-		pr_err("Can't find DSTS");
-		return -ENODEV;
-	}
-
 	/* CWAP allow to define the behavior of the Fn+F2 key,
 	 * this method doesn't seems to be present on Eee PCs */
 	if (asus->driver->quirks->wapf >= 0)