blk-ioc: convert ioc_lookup_icq() to lockless version#76

blktests-ci[bot] wants to merge 4 commits into

linus-master_baselinux-blktests/linux-block:linus-master_basefrom

series/985846=>linus-masterlinux-blktests/linux-block:series/985846=>linus-masterCopy head branch name to clipboard