HID: wacom: Clean up use of struct->wacom_wac

Replace the indirect accesses to struct->wacom_wac from struct->wacom
to the direct access in order for better code reading.
Signed-off-by: Tatsunosuke Tobita <tatsunosuke.tobita@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

drivers/hid/wacom_wac.c

@@ -2983,11 +2983,11 @@ void wacom_wac_report(struct hid_device *hdev, struct hid_report *report)
 
 	wacom_wac_battery_pre_report(hdev, report);
 
-	if (pad_in_hid_field && wacom->wacom_wac.pad_input)
+	if (pad_in_hid_field && wacom_wac->pad_input)
 		wacom_wac_pad_pre_report(hdev, report);
-	if (pen_in_hid_field && wacom->wacom_wac.pen_input)
+	if (pen_in_hid_field && wacom_wac->pen_input)
 		wacom_wac_pen_pre_report(hdev, report);
-	if (finger_in_hid_field && wacom->wacom_wac.touch_input)
+	if (finger_in_hid_field && wacom_wac->touch_input)
 		wacom_wac_finger_pre_report(hdev, report);
 
 	for (r = 0; r < report->maxfield; r++) {
@@ -3003,7 +3003,7 @@ void wacom_wac_report(struct hid_device *hdev, struct hid_report *report)
 
 	wacom_wac_battery_report(hdev, report);
 
-	if (true_pad && wacom->wacom_wac.pad_input)
+	if (true_pad && wacom_wac->pad_input)
 		wacom_wac_pad_report(hdev, report, field);
 }