libxfs: fix buffer log item lifetime weirdness

libxfs: fix buffer log item lifetime weirdness

In xfsprogs, the lifetime of xfs_buf log items doesn't match the kernel
because we keep them around after comitting or cancelling transactions.
This is confusing, so change the lifetime to be consistent.  Worse yet,
if an inode cluster buffer gets bjoined to a transaction (e.g. someone
called xfs_trans_read_buf) we'll leak it when flushing an inode core
back to that buffer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>