floppy: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-6-mcgrof@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/floppy.c

@@ -4697,8 +4697,10 @@ static int __init do_floppy_init(void)
 
 		registered[drive] = true;
 
-		device_add_disk(&floppy_device[drive].dev, disks[drive][0],
-				NULL);
+		err = device_add_disk(&floppy_device[drive].dev,
+				      disks[drive][0], NULL);
+		if (err)
+			goto out_remove_drives;
 	}
 
 	return 0;