md: add error handling support for add_disk()

mainline inclusion
from mainline-v5.16-rc1
commit 9be68dd7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I81XCK

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9be68dd7ac0e13be2ac57770c1f921d6b3294c6e



--------------------------------

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

We just do the unwinding of what was not done before, and are
sure to unlock prior to bailing.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Conflict:
	drivers/md/md.c
	use add_disk_safe().

Signed-off-by: Li Nan <linan122@huawei.com>