staging: comedi: drivers: remove inappropriate COMEDI_CB_EOA events

Hardware errors should be reported with the COMEDI_CB_ERROR event. This event
will cause the async command to cancel. It's not necessary to also set the
COMEDI_CB_EOA event. Remove these events.

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>