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/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index a07055a..caca2c5 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1215,7 +1215,7 @@
 	error = xfs_bmap_finish(&tp, &flist, &committed);
 	if (error)
 		goto bmap_cancel;
-	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+	error = xfs_trans_commit(tp);
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	return error;
 
@@ -5926,8 +5926,7 @@
 	if (error)
 		goto out;
 
-	return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
-
+	return xfs_trans_commit(tp);
 
 out:
 	xfs_trans_cancel(tp);