[bug report] iio: adc: ad7124: change setup reg allocation strategy

[Dan Carpenter <dan.carpenter@linaro.org>]

Hello David Lechner,

Commit 9065197e0d41 ("iio: adc: ad7124: change setup reg allocation
strategy") from Sep 23, 2025 (linux-next), leads to the following
Smatch static checker warning:

	drivers/iio/adc/ad7124.c:595 ad7124_release_config_slot()
	warn: potential bounds check after use 'channel'

drivers/iio/adc/ad7124.c
    587 static void ad7124_release_config_slot(struct ad7124_state *st, u8 channel)
    588 {
    589         unsigned int slot = st->channels[channel].cfg.cfg_slot;
                                    ^^^^^^^^^^^^^^^^^^^^^

    590 
    591         /*
    592          * All of these conditions can happen at probe when all channels are
    593          * disabled. Otherwise, they should not happen normally.
    594          */
--> 595         if (channel >= st->num_channels || slot == AD7124_CFG_SLOT_UNASSIGNED ||
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
If channel is invalid then we would already have read from out of bounds.

    596             st->cfg_slot_use_count[slot] == 0)
    597                 return;
    598 
    599         st->cfg_slot_use_count[slot]--;
    600         st->channels[channel].cfg.cfg_slot = AD7124_CFG_SLOT_UNASSIGNED;
    601 }

regards,
dan carpenter