HID: roccat: Fix "cannot create duplicate filename" problems

Fixing some wrong macro stringification/concatenation.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Achatz <erazor_de@users.sourceforge.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>