uhid(4): update ugd_actlen in USB_GET_REPORT ioctl

USB_GET_REPORT ioctl is documented to update ugd_actlen on return with
the number of bytes copied. It does not do this.

Reviewed by: wulf
PR: 282790
MFC after: 1 week

(cherry picked from commit 0b5d86b38ae9aec92ef96b9227a404a2df3c9234)