block: fix resource leak in blk_register_queue() error path

When registering a queue fails after blk_mq_sysfs_register() is
successful but the function later encounters an error, we need
to clean up the blk_mq_sysfs resources.

Add the missing blk_mq_sysfs_unregister() call in the error path
to properly clean up these resources and prevent a memory leak.

Fixes: 320ae51f ("blk-mq: new multi-queue block IO queueing mechanism")
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250412092554.475218-1-zhengqixing@huaweicloud.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>