efi: Update stale locking comment for struct efivars

struct efivars {

struct efivars {

	/*

	/*

	 * ->lock protects two things:

	 * ->lock protects two things:

	 * 1) ->list - adds, removals, reads, writes

	 * 1) efivarfs_list and efivars_sysfs_list

	 * 2) ops.[gs]et_variable() calls.

	 * 2) ->ops calls

	 * It must not be held when creating sysfs entries or calling kmalloc.

	 * ops.get_next_variable() is only called from register_efivars()

	 * or efivar_update_sysfs_entries(),

	 * which is protected by the BKL, so that path is safe.

	 */

	 */

	spinlock_t lock;

	spinlock_t lock;

	struct kset *kset;

	struct kset *kset;