Substitute USB instances of __attribute__ ((unused)) functions with the
newly introduced __maybe_unused.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>