udev: Don't mark as tablet if device has relative coordinates

Tablets don't typically have relative coordinates (they are separated on
the kernel device layer). However, some Logitech mice report similar
supported events, so use the existence of EV_REL to determiner whether or
not the device is really a tablet.

Fixes bug introduced by 0855ce6772.

Fixes: #26600

src/udev/udev-builtin-input_id.c

@@ -258,7 +258,7 @@ static bool test_pointers(sd_device *dev,
         if (is_tablet && has_pad_buttons)
                 is_tablet_pad = true;
 
-        if (has_pad_buttons && has_wheel) {
+        if (has_pad_buttons && has_wheel && !has_rel_coordinates) {
                 is_tablet = true;
                 is_tablet_pad = true;
         }