staging: comedi: addi_common.h: remove 'ui_AiNbrofScans' from private data

staging: comedi: addi_common.h: remove 'ui_AiNbrofScans' from private data

This member of the private data is a copy of the cmd->stop_arg. Use that
instead.

Fix the b_AiContinuous check in apci3120_ai_cmd(). The (*do_cmdtest) validates
that the cmd->stop_arg os >= 1 for TRIG_COUNT and 0 for TRIG_NONE. The correct
test to set this flag is (cmd->stop_src == TRIG_NONE).

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>