HID: wacom: generic: Clear ABS_MISC when tool leaves proximity

The tool ID information sent in ABS_MISC is expected to be reset to 0
when a tool leaves proximity. Not doing this can cause problems if a
tool is removed and then re-introduced. Kernel event filtering will
prevent the (identical) ABS_MISC event from being sent when the tool
re-enters proxmity. This can cause userspace to not properly set the
tool ID.

Fixes: f85c9dc6 ("HID: wacom: generic: Support tool ID and additional tool types")
Cc: stable # v4.10 <stable@vger.kernel.org>
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_wac.c

@@ -2272,7 +2272,7 @@ static void wacom_wac_pen_report(struct hid_device *hdev,
 		input_report_key(input, wacom_wac->tool[0], prox);
 		if (wacom_wac->serial[0]) {
 			input_event(input, EV_MSC, MSC_SERIAL, wacom_wac->serial[0]);
-			input_report_abs(input, ABS_MISC, id);
+			input_report_abs(input, ABS_MISC, prox ? id : 0);
 		}
 
 		wacom_wac->hid_data.tipswitch = false;