staging:iio:ad7746: Mark transfer buffer as __be32
Fixes the following warnings from sparse:
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
drivers/staging/iio/cdc/ad7746.c:599:25: warning: cast to restricted __be32
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>