hg: jdk/submit: 8243059: Build fails when --with-vendor-name contains a comma

[sgehwolf at redhat.com]

Changeset: b67c2634c522
Author:    sgehwolf
Date:      2020-04-17 11:14 +0200
URL:       https://hg.openjdk.java.net/jdk/submit/rev/b67c2634c522

8243059: Build fails when --with-vendor-name contains a comma
Summary: Use $$(VERSION_CFLAGS) so as to avoid the variable getting evaluated early
Reviewed-by: ihse

! make/launcher/LauncherCommon.gmk