RFR(XS): 8227636: Fix output dir for jlink_jre target in Images.gmk

[Tim Bell]

Hello, Christoph:

> with today’s push for „8227578: Wrong JRE targets in Images.gmk after JDK-8219971” I didn’t catch all issues with the JRE target and especially not the one that’s causing our build errors. But now I’ve got it 😊
>
> Please review this one line fix.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8227636
> Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8227636.0/

Looks good.

Tim