hg: build-infra/jdk9/hotspot: It's unix, not posix nowadays. :)

[magnus.ihse.bursie at oracle.com]

Changeset: 236ac3a32da1
Author:    ihse
Date:      2016-01-22 08:37 +0100
URL:       http://hg.openjdk.java.net/build-infra/jdk9/hotspot/rev/236ac3a32da1

It's unix, not posix nowadays. :)

! makefiles/lib/CreateMapfile.gmk
- makefiles/symbols/symbols-posix
+ makefiles/symbols/symbols-unix