block/rnbd: correct all kernel-doc complaints

Fix all kernel-doc warnings in rnbd-proto.h:
- use correct enum name in kdoc comment
- mark several struct members as "/* private: */" so that no kdoc is
required for them
- don't use "/**" for a non-kernel-doc comment
- use the correct struct member name for "dev_name"
- use " *" for a blank kernel-doc line

Fixes these warnings:
Warning: drivers/block/rnbd/rnbd-proto.h:41 expecting prototype for
enum rnbd_msg_types. Prototype was for enum rnbd_msg_type instead
Warning: drivers/block/rnbd/rnbd-proto.h:50 struct member '__padding'
not described in 'rnbd_msg_hdr'
Warning: drivers/block/rnbd/rnbd-proto.h:53 This comment starts with
'/**', but isn't a kernel-doc comment.
* We allow to map RO many times and RW only once. We allow to map yet another
Warning: drivers/block/rnbd/rnbd-proto.h:81 struct member 'reserved'
not described in 'rnbd_msg_sess_info'
Warning: drivers/block/rnbd/rnbd-proto.h:92 struct member 'reserved'
not described in 'rnbd_msg_sess_info_rsp'
Warning: drivers/block/rnbd/rnbd-proto.h:107 struct member 'resv1'
not described in 'rnbd_msg_open'
Warning: drivers/block/rnbd/rnbd-proto.h:107 struct member 'dev_name'
not described in 'rnbd_msg_open'
Warning: drivers/block/rnbd/rnbd-proto.h:107 struct member 'reserved'
not described in 'rnbd_msg_open'
Warning: drivers/block/rnbd/rnbd-proto.h:158 struct member 'reserved'
not described in 'rnbd_msg_open_rsp'
Warning: drivers/block/rnbd/rnbd-proto.h:189 bad line:

Signed-off-by: Randy Dunlap <[e-mail]>
Acked-by: Jack Wang <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/rnbd/rnbd-proto.h

···
 #define RTRS_PORT 1234
 
 /**
- * enum rnbd_msg_types - RNBD message types
+ * enum rnbd_msg_type - RNBD message types
  * @RNBD_MSG_SESS_INFO:	initial session info from client to server
  * @RNBD_MSG_SESS_INFO_RSP:	initial session info from server to client
  * @RNBD_MSG_OPEN:		open (map) device request
···
  */
 struct rnbd_msg_hdr {
 	__le16		type;
+	/* private: */
 	__le16		__padding;
 };
 
-/**
+/*
  * We allow to map RO many times and RW only once. We allow to map yet another
  * time RW, if MIGRATION is provided (second RW export can be required for
  * example for VM migration)
···
 struct rnbd_msg_sess_info {
 	struct rnbd_msg_hdr hdr;
 	u8		ver;
+	/* private: */
 	u8		reserved[31];
 };
 
···
 struct rnbd_msg_sess_info_rsp {
 	struct rnbd_msg_hdr hdr;
 	u8		ver;
+	/* private: */
 	u8		reserved[31];
 };
 
···
  * @hdr:		message header
  * @access_mode:	the mode to open remote device, valid values see:
  *			enum rnbd_access_mode
- * @device_name:	device path on remote side
+ * @dev_name:		device path on remote side
  */
 struct rnbd_msg_open {
 	struct rnbd_msg_hdr hdr;
 	u8		access_mode;
+	/* private: */
 	u8		resv1;
+	/* public: */
 	s8		dev_name[NAME_MAX];
+	/* private: */
 	u8		reserved[3];
 };
 
···
 	__le16			secure_discard;
 	u8			obsolete_rotational;
 	u8			cache_policy;
+	/* private: */
 	u8			reserved[10];
 };
 
···
  * @RNBD_OP_DISCARD:        discard sectors
  * @RNBD_OP_SECURE_ERASE:   securely erase sectors
  * @RNBD_OP_WRITE_ZEROES:   write zeroes sectors
-
+ *
  * @RNBD_F_SYNC:	     request is sync (sync write or read)
  * @RNBD_F_FUA:             forced unit access
  */