dm: Refactor is_abnormal_io()

Use a single switch-case to simplify is_abnormal_io() and make this
function more readable and easier to modify.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/dm.c

@@ -1598,20 +1598,18 @@ static void __send_abnormal_io(struct clone_info *ci, struct dm_target *ti,
 
 static bool is_abnormal_io(struct bio *bio)
 {
-	enum req_op op = bio_op(bio);
-
-	if (op != REQ_OP_READ && op != REQ_OP_WRITE && op != REQ_OP_FLUSH) {
-		switch (op) {
-		case REQ_OP_DISCARD:
-		case REQ_OP_SECURE_ERASE:
-		case REQ_OP_WRITE_ZEROES:
-			return true;
-		default:
-			break;
-		}
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
+	case REQ_OP_WRITE:
+	case REQ_OP_FLUSH:
+		return false;
+	case REQ_OP_DISCARD:
+	case REQ_OP_SECURE_ERASE:
+	case REQ_OP_WRITE_ZEROES:
+		return true;
+	default:
+		return false;
 	}
-
-	return false;
 }
 
 static blk_status_t __process_abnormal_io(struct clone_info *ci,