[PATCH] USB gadget: drain rndis response queue on disconnect

Drain the rndis response queue on disconnect.  This fixes a problem
in which an rndis response left in the queue from a previous session
could cause a subsequent session to fail.

Signed-off-by: Andy Lowe <alowe@mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>