usb: preserve error when doing request

Currently, USB request not distinguished different error and always return EIO.
However, some error are recoverable or ignorable in userspace.
Therefore, we preserve the meaning of different error to userspace then
allow userspace to decide how to use the return error.

Reviewed by: adrian
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D52244