[libmanette] device: Remove unused force_feedback_id struct member

[Adrien Plazas <aplazas src gnome org>]

commit d306b6c61ac82a59d0717663ae4aa72845dd2c31
Author: vanadiae <vanadiae35 gmail com>
Date:   Sat Oct 17 19:31:12 2020 +0200

    device: Remove unused force_feedback_id struct member
    
    It wasn't used anywhere in the code.

 src/manette-device.c | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/src/manette-device.c b/src/manette-device.c
index 62d4e0d..af6faf0 100644
--- a/src/manette-device.c
+++ b/src/manette-device.c
@@ -51,7 +51,6 @@ struct _ManetteDevice
   ManetteMapping *mapping;
 
   struct ff_effect rumble_effect;
-  gint16 force_feedback_id;
 };
 
 G_DEFINE_TYPE (ManetteDevice, manette_device, G_TYPE_OBJECT)