staging: comedi: me4000: remove 'chan' check in me4000_ai_insn_read()

The comedi core validates that the 'chan' is valid for the subdevice
before calling the (*insn_read) operation. Remove the unnecessary check.

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>
1 file changed