devlink: make devlink_flash_overwrite enum named one

Since this enum is going to be used in generated userspace file, name it
properly.

Signed-off-by: Jiri Pirko <[e-mail]>
Reviewed-by: Jacob Keller <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/uapi/linux/devlink.h

···
  * Documentation/networking/devlink/devlink-flash.rst
  *
  */
-enum {
+enum devlink_flash_overwrite {
 	DEVLINK_FLASH_OVERWRITE_SETTINGS_BIT,
 	DEVLINK_FLASH_OVERWRITE_IDENTIFIERS_BIT,