iio: health: afe4404: Fix oob read in afe4404_[read|write]_raw

In the Linux kernel, the following vulnerability has been resolved: iio: health: afe4404: Fix oob read in afe4404_[read|write]_raw KASAN report out-of-bounds read as follows: BUG: KASAN: global-out-of-bounds in afe4404_read_raw+0x2ce/0x380 Read of size 4 at addr ffffffffc00e4658 by task cat/278 Call Trace: afe4404_read_raw iio_read_channel_info dev_attr_show The buggy address belongs to the variable: afe4404_channel_leds+0x18/0xffffffffffffe9c0 This issue can be reproduce by singe command: $ cat /sys/bus/i2c/devices/0-0058/iio\:device0/in_intensity6_raw The array size of afe4404_channel_leds and afe4404_channel_offdacs are less than channels, so access with chan->address cause OOB read in afe4404_[read|write]_raw. Fix it by moving access before use them.