[PATCH] jbd: add lock annotation to jbd_sync_bh

jbd_sync_bh releases journal->j_list_lock.  Add a lock annotation to this
function so that sparse can check callers for lock pairing, and so that
sparse will not complain about this function since it intentionally uses
the lock in this manner.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>