Staging: comedi: comedi_fops: Avoid orphaned proc entry

Move comedi_proc_init to the end to avoid orphaned proc entry
if module loading failed.

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>