staging: iio: meter: Remove explicit comparisons

Remove comparisons to 0 or NULL
Signed-off-by: Cristina Moraru <cristina.moraru09@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/meter/ade7753.c

@@ -406,7 +406,7 @@ static ssize_t ade7753_write_frequency(struct device *dev,
 	ret = kstrtou16(buf, 10, &val);
 	if (ret)
 		return ret;
-	if (val == 0)
+	if (!val)
 		return -EINVAL;
 
 	mutex_lock(&indio_dev->mlock);

drivers/staging/iio/meter/ade7754.c

@@ -438,7 +438,7 @@ static ssize_t ade7754_write_frequency(struct device *dev,
 	ret = kstrtou16(buf, 10, &val);
 	if (ret)
 		return ret;
-	if (val == 0)
+	if (!val)
 		return -EINVAL;
 
 	mutex_lock(&indio_dev->mlock);

drivers/staging/iio/meter/ade7759.c

@@ -377,7 +377,7 @@ static ssize_t ade7759_write_frequency(struct device *dev,
 	ret = kstrtou16(buf, 10, &val);
 	if (ret)
 		return ret;
-	if (val == 0)
+	if (!val)
 		return -EINVAL;
 
 	mutex_lock(&indio_dev->mlock);

drivers/staging/iio/meter/ade7854-spi.c

@@ -278,7 +278,7 @@ static int ade7854_spi_probe(struct spi_device *spi)
 	struct iio_dev *indio_dev;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
-	if (indio_dev == NULL)
+	if (!indio_dev)
 		return -ENOMEM;
 	st = iio_priv(indio_dev);
 	spi_set_drvdata(spi, indio_dev);