ataflop: address add_disk() error handling on probe

We need to cleanup resources on the probe() callback registered
with __register_blkdev(), now that add_disk() error handling is
supported. Address this.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-13-mcgrof@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/ataflop.c

@@ -2018,12 +2018,18 @@ static void ataflop_probe(dev_t dev)
 
 	if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS)
 		return;
-	if (!unit[drive].disk[type]) {
-		if (ataflop_alloc_disk(drive, type) == 0) {
-			add_disk(unit[drive].disk[type]);
-			unit[drive].registered[type] = true;
-		}
-	}
+	if (unit[drive].disk[type])
+		return
+	if (ataflop_alloc_disk(drive, type))
+		return;
+	if (add_disk(unit[drive].disk[type]))
+		goto cleanup_disk;
+	unit[drive].registered[type] = true;
+	return;
+
+cleanup_disk:
+	blk_cleanup_disk(unit[drive].disk[type]);
+	unit[drive].disk[type] = NULL;
 }
 
 static void atari_floppy_cleanup(void)