Staging: iio: Use braces on all arms of if statement

Add braces to improve consistency when using if statements.
Found by checkpatch.pl:
"CHECK: braces {} should be used on all arms of this statement".
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Reviewed-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/frequency/ad9834.c

@@ -111,9 +111,9 @@ static ssize_t ad9834_write(struct device *dev,
 		break;
 	case AD9834_FSEL:
 	case AD9834_PSEL:
-		if (val == 0)
+		if (val == 0) {
 			st->control &= ~(this_attr->address | AD9834_PIN_SW);
-		else if (val == 1) {
+		} else if (val == 1) {
 			st->control |= this_attr->address;
 			st->control &= ~AD9834_PIN_SW;
 		} else {