vtruncbuf: add a comment explaining the purpose of the loop
vtruncbuf: improve the check for meta buffer Revision e99215a614675 reorganized the code in vtruncbuf(), and moved the logic to flush meta buffers into a dedicated loop. While doing it, the condition was changed from bp->b_lblkno < 0 (to handle) into bp->b_lblkno > 0 (to skip), which causes buffer at lblkno to needlessly flush.