kyber: fix kabi broken in ->bio_merge()

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I96DIN


CVE: CVE-2021-46984

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Fix kabi as follows:
1. Revert origin path.
Revert "kyber: fix out of bounds access when preempted"

2. Use a new way to fix issue:
Mainline fixed this issue by passing a request_queue instead of hctx to
->bio_merge() and get hctx in kyber_bio_merge(), but it changed kabi.
In redhat-8.1.x, keep passing hctx, use hctx to get request_queue, and
get hctx in kyber_bio_merge() again, so that kabi will not be changed.

Fixes: efed9a33 ("kyber: fix out of bounds access when preempted")
Signed-off-by: Li Nan <linan122@huawei.com>