bcachefs: Fix six_lock_readers_add()

Have to be careful with bit fields - when subtracting, this was
overflowing into the write_locking bit.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2022-09-01 22:05:16 -04:00
commit 6b81f194f3