HID: samples: fix the 2 struct_ops definitions

Turns out that this is not compiling anymore because the hid_bpf_ops
struct_ops definition had a change during the revisions.

Fixes: e342d6f6

 ("HID: samples: convert the 2 HID-BPF samples into struct_ops")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>