staging: iio: accel: Use __be16 instead of u16

This patch fixes these warning messages found by sparse:
drivers/staging/iio/accel/sca3000_ring.c:120:61: warning: incorrect type in argument 1 (different base types)
drivers/staging/iio/accel/sca3000_ring.c:120:61:    expected restricted __be16 const [usertype] *p
drivers/staging/iio/accel/sca3000_ring.c:120:61:    got unsigned short [usertype] *

Signed-off-by: Aybuke Ozdemir <aybuke.147@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/accel/sca3000_ring.c

@@ -117,7 +117,7 @@ static int sca3000_read_first_n_hw_rb(struct iio_buffer *r,
 		goto error_ret;
 
 	for (i = 0; i < num_read; i++)
-		*(((u16 *)rx) + i) = be16_to_cpup((u16 *)rx + i);
+		*(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i);
 
 	if (copy_to_user(buf, rx, num_read))
 		ret = -EFAULT;