staging/nvec: fix compilation error in nvec.c

This fixes a compilation error in nvec.c due to the missing module.h include.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Cc: Julian Andres Klode <jak@jak-linux.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>