null_blk: fix ida error handling in null_add_dev()

stable inclusion
from stable-v5.10.137
commit 7a4b46784a7b27b5ceb28bc816ea188d6d035dfa
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7a4b46784a7b27b5ceb28bc816ea188d6d035dfa



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[ Upstream commit ee452a8d ]

There needs to be some error checking if ida_simple_get() fails.
Also call ida_free() if there are errors later.

Fixes: 94bc02e3 ("nullb: use ida to manage index")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YtEhXsr6vJeoiYhd@kili


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>