touchpad: explicitly init scroll settings

No effect, we're just initializing with the same value we did before. What is
important here is the comment, the touchpad scroll threshold is in mm
for touchpads providing a resolution.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

src/evdev-mt-touchpad.c

@@ -956,6 +956,9 @@ tp_init_scroll(struct tp_dispatch *tp)
 	tp->scroll.natural_scrolling_enabled = false;
 	tp->device->base.config.natural_scroll = &tp->scroll.config;
 
+	/* In mm for touchpads with valid resolution, see tp_init_accel() */
+	tp->device->scroll.threshold = 5.0;
+
 	return 0;
 }