Staging: comedi: comedi_fops: Remove redundant init.h header

After commit 0fd972a7 ("module: relocate module_init
from init.h to module.h"), including module.h will do and
init.h is also thrown in.

Signed-off-by: Cheah Kok Cheong <thrust73@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>