staging: comedi: jr3_pci: rename struct poll_delay_t

Rename this private struct so it has namespace associated with the
driver.

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