RFR: JDK-8171167: Build fails in Mach 5 with "File name too long."

[Tim Bell]

Erik:

> Please review this small fix, correcting a mistake in
> https://bugs.openjdk.java.net/browse/JDK-8170878. I generate a temporary
> file to store the file list to be included in each bundle, for each src
> root dir. The problem is that to make the file unique, I used the full
> path of the src root dir. In this patch, I cut off the part outside the
> TOPDIR of the workspace. That part will be the same for any src root
> anyway so cutting it will not affect uniqueness.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8171167
>
> Webrev: http://cr.openjdk.java.net/~erikj/8171167/webrev.01/
>

Looks good.

/Tim