[PATCH] USB: usbnet, zaurus mtu fixup

This includes an MTU fixup which could affect larger packets with newer
Zaurii, described as http://bugzilla.kernel.org/show_bug.cgi?id=6286;
plus minor whitespace cleanup.

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