More bcachefs bugfixes for 6.7:

 - Fix a deadlock in the data move path with nocow locks (vs. update in
   place writes); when trylock failed we were incorrectly waiting for in
   flight ios to flush.
 - Fix reporting of NFS file handle length
 - Fix early error path in bch2_fs_alloc() - list head wasn't being
   initialized early enough
 - Make sure correct (hardware accelerated) crc modules get loaded
 - Fix a rare overflow in the btree split path, when the packed bkey
   format grows and all the keys have no value (LRU btree).
 - Fix error handling in the sector allocator
   This was causing writes to spuriously fail in multidevice setups, and
   another bug meant that the errors weren't being logged, only reported
   via fsync.