[PATCH] Fix default value for commit interval for older reiserfs filesystems.

[PATCH] Fix default value for commit interval for older reiserfs filesystems.

From: Bart Samwel <bart@samwel.tk>

The reiserfs patch that adds support for "commit=0" saves the default max
commit age in a variable when the fs is originally mounted, so that it can
later restore it.  Unfortunately it makes some mistakes with that:

- The default is not saved when the original mount has a commit=NNN option.

- The default is not correctly saved for older reiserfs filesystems, where
  the default was not stored on disk.

This patch fixes these mistakes.