Staging: iio: fix up the iio_get_new_idr_val comment

improve the comment a bit

Cc: Greg KH <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Sonic Zhang <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/iio/industrialio-core.c

···
 	sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 }
 
-/* This function return negative value if fails. */
+/* Return a negative errno on failure */
 int iio_get_new_idr_val(struct idr *this_idr)
 {
 	int ret;