iio: sca3000: Potential endian bug in sca3000_read_event_value()

The problem is that "ret" is an int but we're casting it as
"(unsigned long *)&ret" when we do the for_each_set_bit() loop.  This
will not work on big endian 64 bit systems.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>