remove parent parameter from dissect_usb_setup_response()

Change-Id: Ib4a5cc3b783d3a4a1477624678964a9627d582e6
Reviewed-on: https://code.wireshark.org/review/5191
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
Tested-by: Martin Kaiser <wireshark@kaiser.cx>