nvmet: reorder fields in 'struct nvme_dhchap_queue_context'

Group some variables based on their sizes to reduce holes.
On x86_64, this shrinks the size of 'struct nvme_dhchap_queue_context' from
416 to 400 bytes.

This structure is kvcalloc()'ed in nvme_auth_init_ctrl(), so it is likely
that the allocation can be relatively big. Saving 16 bytes per structure
may might a slight difference.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/auth.c

@@ -30,18 +30,18 @@ struct nvme_dhchap_queue_context {
 	u32 s2;
 	u16 transaction;
 	u8 status;
+	u8 dhgroup_id;
 	u8 hash_id;
 	size_t hash_len;
-	u8 dhgroup_id;
 	u8 c1[64];
 	u8 c2[64];
 	u8 response[64];
 	u8 *host_response;
 	u8 *ctrl_key;
-	int ctrl_key_len;
 	u8 *host_key;
-	int host_key_len;
 	u8 *sess_key;
+	int ctrl_key_len;
+	int host_key_len;
 	int sess_key_len;
 };