staging: serqt_usb2: Fixed coding style CamelCases

Changed names of several variables, that contained CamelCases.

Signed-off-by: Bernd Bassimir <bassimir.kernel@gmx.de>
Signed-off-by: Nico Doerr <nico.doerr@hawo.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>