bcachefs: Fix a scheduler splat in __bch2_next_write_buffer_flush_journal_buf()

We're using mutex_lock() inside a wait_event() conditional -
prepare_to_wait() has already flipped task state, so potentially
blocking ops need annotation.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-05-06 10:14:13 -04:00
commit 72e71bf029