Staging: iio: Documentation: Added check for sscanf return value.

The following patch fixes the following checkpatch.pl warning by adding
a check for sscanf return value.
WARNING: unchecked sscanf return value.
Signed-off-by: Heena Sirwani <heenasirwani@gmail.com>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/Documentation/lsiio.c

@@ -63,9 +63,12 @@ static int dump_one_device(const char *dev_dir_name)
 {
 	char name[IIO_MAX_NAME_LENGTH];
 	int dev_idx;
+	int retval;
 
-	sscanf(dev_dir_name + strlen(iio_dir) + strlen(type_device),
+	retval = sscanf(dev_dir_name + strlen(iio_dir) + strlen(type_device),
 			"%i", &dev_idx);
+	if (retval != 1)
+		return -EINVAL;
 	read_sysfs_string("name", dev_dir_name, name);
 	printf("Device %03d: %s\n", dev_idx, name);
 
@@ -78,9 +81,12 @@ static int dump_one_trigger(const char *dev_dir_name)
 {
 	char name[IIO_MAX_NAME_LENGTH];
 	int dev_idx;
+	int retval;
 
-	sscanf(dev_dir_name + strlen(iio_dir) + strlen(type_trigger),
+	retval = sscanf(dev_dir_name + strlen(iio_dir) + strlen(type_trigger),
 			"%i", &dev_idx);
+	if (retval != 1)
+		return -EINVAL;
 	read_sysfs_string("name", dev_dir_name, name);
 	printf("Trigger %03d: %s\n", dev_idx, name);
 	return 0;