iio: adc: pac1921: replace sprintf() with sysfs_emit()

Update the pac1921_read_label() function to use sysfs_emit() for
generating labels.

Signed-off-by: Nuno Sá <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/adc/pac1921.c

···
 {
 	switch (chan->channel) {
 	case PAC1921_CHAN_VBUS:
-		return sprintf(label, "vbus\n");
+		return sysfs_emit(label, "vbus\n");
 	case PAC1921_CHAN_VSENSE:
-		return sprintf(label, "vsense\n");
+		return sysfs_emit(label, "vsense\n");
 	case PAC1921_CHAN_CURRENT:
-		return sprintf(label, "current\n");
+		return sysfs_emit(label, "current\n");
 	case PAC1921_CHAN_POWER:
-		return sprintf(label, "power\n");
+		return sysfs_emit(label, "power\n");
 	default:
 		return -EINVAL;
 	}