iio: temperature: ltc2983: allocate iio channels once

Currently, every time the device wakes up from sleep, the
iio_chan array is reallocated, leaking the previous one
until the device is removed (basically never).

Move the allocation to the probe function to avoid this.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Fixes: f110f31 ("iio: temperature: Add support for LTC2983")
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221014123724.1401011-2-demonsingur@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: Cosmin Tanislav

drivers/iio/temperature/ltc2983.c

@@ -1385,13 +1385,6 @@ static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 		return ret;
 	}
 
-	st->iio_chan = devm_kzalloc(&st->spi->dev,
-				    st->iio_channels * sizeof(*st->iio_chan),
-				    GFP_KERNEL);
-
-	if (!st->iio_chan)
-		return -ENOMEM;
-
 	ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
 				 LTC2983_NOTCH_FREQ_MASK,
 				 LTC2983_NOTCH_FREQ(st->filter_notch_freq));
@@ -1514,6 +1507,12 @@ static int ltc2983_probe(struct spi_device *spi)
 		gpiod_set_value_cansleep(gpio, 0);
 	}
 
+	st->iio_chan = devm_kzalloc(&spi->dev,
+				    st->iio_channels * sizeof(*st->iio_chan),
+				    GFP_KERNEL);
+	if (!st->iio_chan)
+		return -ENOMEM;
+
 	ret = ltc2983_setup(st, true);
 	if (ret)
 		return ret;