xfs: saner xfs_trans_commit interface

The flags argument to xfs_trans_commit is not useful for most callers, as
a commit of a transaction without a permanent log reservation must pass
0 here, and all callers for a transaction with a permanent log reservation
except for xfs_trans_roll must pass XFS_TRANS_RELEASE_LOG_RES.  So remove
the flags argument from the public xfs_trans_commit interfaces, and
introduce low-level __xfs_trans_commit variant just for xfs_trans_roll
that regrants a log reservation instead of releasing it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index c4ba36d..eac9549 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -795,7 +795,7 @@
 	spin_unlock(&mp->m_sb_lock);
 	xfs_log_sb(tp);
 
-	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+	error = xfs_trans_commit(tp);
 	if (error) {
 		ASSERT(XFS_FORCED_SHUTDOWN(mp));
 		xfs_alert(mp, "%s failed (error %d)!", __func__, error);