Return error on fcmh modify.
Return error on fcmh modify.

tested with svn 25669.  In general, it works good for my four way parallel test.  But it fails twice
with tar over ssh:

linux-git/README
tar: Exiting with failure status due to previous errors
zhihui@born-of-fire:~$

Also self build failed with known errors (could be a dir cache issue).

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable