The reworked Ethernet gadget has an RNDIS interop problem when used
with the CDC subset driver ... e.g. on PXA 2xx and 3xx hardware,
which currently has a hard time talking to MS-Windows hosts.

The issue is that Microsoft requires USB_CLASS_COMM.  Fix by tweaking
the CDC subset driver to not switch to USB_CLASS_VENDOR_SPEC if RNDIS
is used in some other device configuration.

[ UPDATED:  some "statements" were comma-terminated; fix that. ]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Aric Blumer <aric@sdgsystems.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>