USB: unusual_devs device removal

This entry has been a mystery for some time. I had sent this patch as an
RFC a while ago, and now we've had two reports of this not being needed,
so I'm removing it.

In the event there are reports of breakage, we should revert this patch,
but add a US_FL_NEED_OVERRIDE flag.

Signed-off-by: Phil Dibowitz <phil@ipom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>