xfs: cleanup up xfs_log_force calling conventions

Remove the XFS_LOG_FORCE argument which was always set, and the
XFS_LOG_URGE define, which was never used.

Split xfs_log_force into a two helpers - xfs_log_force which forces
the whole log, and xfs_log_force_lsn which forces up to the
specified LSN.  The underlying implementations already were entirely
separate, as were the users.

Also re-indent the new _xfs_log_force/_xfs_log_force which
previously had a weird coding style.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

fs/xfs/xfs_trans.c

@@ -981,9 +981,8 @@ shut_us_down:
 	 */
 	if (sync) {
 		if (!error) {
-			error = _xfs_log_force(mp, commit_lsn,
-				      XFS_LOG_FORCE | XFS_LOG_SYNC,
-				      log_flushed);
+			error = _xfs_log_force_lsn(mp, commit_lsn,
+				      XFS_LOG_SYNC, log_flushed);
 		}
 		XFS_STATS_INC(xs_trans_sync);
 	} else {