HID: wacom: add missed stylus_in_proximity line back

Commit 7e12978 ("HID: wacom: break out wacom_intuos_get_tool_type") by accident
removed stylus_in_proximity flag for Intuos series while shuffling the code
around.

Fix that by reintroducing that flag setting in wacom_intuos_inout(), where
it originally was.

Fixes: 7e12978 ("HID: wacom: break out wacom_intuos_get_tool_type")
Signed-off-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_wac.c

@@ -684,6 +684,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 
 		wacom->tool[idx] = wacom_intuos_get_tool_type(wacom->id[idx]);
 
+		wacom->shared->stylus_in_proximity = true;
 		return 1;
 	}