*** not correct for time skew

[karl]

In make's time skew warning message:

    make[2]: *** Warning: File `file' has modification time in the future
    (2001-01-16 05:55:30.3184 > 2001-01-16 05:55:30.170387819)

I really strongly believe the *** should not be used.  This is a
warning, not an error.  In every other case that I know of, *** is
reserved for actual errors that prevent make from completing.  I've
reported this before, but it's still present in 3.79.1.

I (and doubtless many others) have numerous scripts which check for 
build failures by searching for ***.

Thanks,
address@hidden