staging: iio: adis16240: fix sparse warnings regarding incorrect argument type

Silence the following sparse warnings by changing cast from u16 to
__be16:

  CHECK   drivers/staging/iio/accel/adis16240_core.c
drivers/staging/iio/accel/adis16240_core.c:128:51: warning: incorrect
type in argument 3 (different signedness)
drivers/staging/iio/accel/adis16240_core.c:128:51:    expected unsigned
short [usertype] *val
drivers/staging/iio/accel/adis16240_core.c:128:51:    got signed short
*<noident>
drivers/staging/iio/accel/adis16240_core.c:142:51: warning: incorrect
type in argument 3 (different signedness)
drivers/staging/iio/accel/adis16240_core.c:142:51:    expected unsigned
short [usertype] *val
drivers/staging/iio/accel/adis16240_core.c:142:51:    got signed short
*<noident>
Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/resolver/ad2s1210.c

@@ -491,7 +491,7 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
 
 	switch (chan->type) {
 	case IIO_ANGL:
-		pos = be16_to_cpup((u16 *)st->rx);
+		pos = be16_to_cpup((__be16 *) st->rx);
 		if (st->hysteresis)
 			pos >>= 16 - st->resolution;
 		*val = pos;
@@ -499,7 +499,7 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
 		break;
 	case IIO_ANGL_VEL:
 		negative = st->rx[0] & 0x80;
-		vel = be16_to_cpup((s16 *)st->rx);
+		vel = be16_to_cpup((__be16 *) st->rx);
 		vel >>= 16 - st->resolution;
 		if (vel & 0x8000) {
 			negative = (0xffff >> st->resolution) << st->resolution;