staging: comedi: me4000: use comedi_buf_write_samples()

Use comedi_buf_write_samples() to add the sample to the async buffer.

The async events COMEDI_CB_OVERFLOW will be set by the core if the async
buffer overflows. A dev_warn() message will also be output by the core
if the buffer overflows. Remove the unnecessary event and the dev_err()
messages in the driver.

The core will also add the COMEDI_CB_BLOCK event when data is written
to the async buffer. Remove these unnecessary events from the driver.

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>