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_ioctl.c b/fs/xfs/xfs_ioctl.c
index 3abd3c4..ea7d85a 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -346,7 +346,7 @@
 	ip->i_d.di_dmstate  = state;
 
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-	error = xfs_trans_commit(tp, 0);
+	error = xfs_trans_commit(tp);
 
 	return error;
 }
@@ -1253,7 +1253,7 @@
 	else
 		ip->i_d.di_extsize = 0;
 
-	code = xfs_trans_commit(tp, 0);
+	code = xfs_trans_commit(tp);
 
 	/*
 	 * Release any dquot(s) the inode had kept before chown.
@@ -1342,7 +1342,7 @@
 		goto out_drop_write;
 	}
 
-	error = xfs_trans_commit(tp, 0);
+	error = xfs_trans_commit(tp);
 out_drop_write:
 	mnt_drop_write_file(filp);
 	return error;