block: fix enum descriptions kernel-doc

Fix all kernel-doc warnings in blk_types.h:

Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_READ' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_WRITE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_FLUSH' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DISCARD' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_SECURE_ERASE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_APPEND' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_WRITE_ZEROES' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_OPEN' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_CLOSE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_FINISH' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_RESET' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_RESET_ALL' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DRV_IN' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DRV_OUT' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_LAST' not described in enum 'req_op'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: rddunlap

include/linux/blk_types.h

@@ -345,32 +345,33 @@ typedef __u32 __bitwise blk_mq_req_flags_t;
  * meaning.
  */
 enum req_op {
-	/* read sectors from the device */
+	/** @REQ_OP_READ: read sectors from the device */
 	REQ_OP_READ		= (__force blk_opf_t)0,
-	/* write sectors to the device */
+	/** @REQ_OP_WRITE: write sectors to the device */
 	REQ_OP_WRITE		= (__force blk_opf_t)1,
-	/* flush the volatile write cache */
+	/** @REQ_OP_FLUSH: flush the volatile write cache */
 	REQ_OP_FLUSH		= (__force blk_opf_t)2,
-	/* discard sectors */
+	/** @REQ_OP_DISCARD: discard sectors */
 	REQ_OP_DISCARD		= (__force blk_opf_t)3,
-	/* securely erase sectors */
+	/** @REQ_OP_SECURE_ERASE: securely erase sectors */
 	REQ_OP_SECURE_ERASE	= (__force blk_opf_t)5,
-	/* write data at the current zone write pointer */
+	/** @REQ_OP_ZONE_APPEND: write data at the current zone write pointer */
 	REQ_OP_ZONE_APPEND	= (__force blk_opf_t)7,
-	/* write the zero filled sector many times */
+	/** @REQ_OP_WRITE_ZEROES: write the zero filled sector many times */
 	REQ_OP_WRITE_ZEROES	= (__force blk_opf_t)9,
-	/* Open a zone */
+	/** @REQ_OP_ZONE_OPEN: Open a zone */
 	REQ_OP_ZONE_OPEN	= (__force blk_opf_t)11,
-	/* Close a zone */
+	/** @REQ_OP_ZONE_CLOSE: Close a zone */
 	REQ_OP_ZONE_CLOSE	= (__force blk_opf_t)13,
-	/* Transition a zone to full */
+	/** @REQ_OP_ZONE_FINISH: Transition a zone to full */
 	REQ_OP_ZONE_FINISH	= (__force blk_opf_t)15,
-	/* reset a zone write pointer */
+	/** @REQ_OP_ZONE_RESET: reset a zone write pointer */
 	REQ_OP_ZONE_RESET	= (__force blk_opf_t)17,
-	/* reset all the zone present on the device */
+	/** @REQ_OP_ZONE_RESET_ALL: reset all the zone present on the device */
 	REQ_OP_ZONE_RESET_ALL	= (__force blk_opf_t)19,
 
 	/* Driver private requests */
+	/* private: */
 	REQ_OP_DRV_IN		= (__force blk_opf_t)34,
 	REQ_OP_DRV_OUT		= (__force blk_opf_t)35,