Revert "usb: roles: fix NULL pointer issue when put module's reference"

This reverts commit ef982fc4 which is
commit 1c9be138 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.  It's not a "real" break, and
we can work around it, but this really does not affect Android systems,
so it's safe to drop for now.

Bug: 161946584
Change-Id: Ica8f15560c09d1077c4177fb7710c5a24a563360
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>