nbd: remove the call to set_blocksize

mainline inclusion
from mainline-v5.11-rc1
commit ee4bf648
category: bugfix
bugzilla: 187706,https://gitee.com/openeuler/kernel/issues/I5XEBX
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee4bf648635055d2b76afadaf34236c8b2d852a7



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Block driver have no business setting the file system concept of a
block size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

conflicts:
	drivers/block/nbd.c

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>