Revert "usb: roles: don't get/set_role() when usb_role_switch is unregistered"

This reverts commit 2f414a56 which is
commit b787a3e7 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ia72bbe97772c8e65c2dfe2835b00a49414702dbb
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>