commit 7d064363 upstream.

Triggered buffers shouldn't return processed data, and the respective
conversion was overflowing the defined .realbits for the channel.

Cc: george.mccollister@gmail.com
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>