bcachefs bugfixes for 6.7 Lots of small fixes for minor nits and compiler warnings. Bigger items: - The six locks lost wakeup is finally fixed: six_read_trylock() was checking for the waiting bit before decrementing the number of readers - validated the fix with a torture test. - Fix for a memory reclaim issue: when needing to reallocate a key cache key, we now do our usual GFP_NOWAIT; unlock(); GFP_KERNEL dance. - Multiple deleted inodes btree fixes - Fix an issue in fsck, where i_nlink would be recalculated incorrectly for hardlinked files if a snapshot had ever been taken. - Kill journal pre-reservations: This is a bigger patch than I would normally send at this point, but it deletes code and it fixes some of our tests that would sporadically die with the journal getting stuck, and it's a performance improvement, too.