staging: iio: frequency: 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/frequency/ad9834.c

@@ -111,7 +111,7 @@ static ssize_t ad9834_write(struct device *dev,
 		break;
 	case AD9834_FSEL:
 	case AD9834_PSEL:
-		if (val == 0) {
+		if (!val) {
 			st->control &= ~(this_attr->address | AD9834_PIN_SW);
 		} else if (val == 1) {
 			st->control |= this_attr->address;