gpio: uapi: Improve phrasing around arrays representing empty strings

 * struct gpiochip_info - Information about a certain GPIO chip

 * @name: the Linux kernel name of this GPIO chip

 * @label: a functional name for this GPIO chip, such as a product

 * number, may be NULL

 * number, may be empty

 * @lines: number of GPIO lines on this chip

 */

struct gpiochip_info {

 * @flags: various flags for this line

 * @name: the name of this GPIO line, such as the output pin of the line on the

 * chip, a rail or a pin header name on a board, as specified by the gpio

 * chip, may be NULL

 * chip, may be empty

 * @consumer: a functional name for the consumer of this GPIO line as set by

 * whatever is using it, will be NULL if there is no current user but may

 * also be NULL if the consumer doesn't set this up

 * whatever is using it, will be empty if there is no current user but may

 * also be empty if the consumer doesn't set this up

 */

struct gpioline_info {

	__u32 line_offset;