staging: comedi: pcmuio: kzalloc'ed data does not need cleared

The 'subpriv' pointer is kzalloc'ed during the attach.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>