Fix postinst script of sys-apps/baselayout-java

The old postinst will not work for binpkg. This CL fixes it.

BUG=b:168655853
TEST=emerge a binpkg built with EROOT=/build/whatever.
TEST=check /etc/ssl/certs/java/cacerts exists.

Change-Id: I20a1904568e69e7c59adcb9a55b9498305cb9c83
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2566311
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Boleyn Su <boleynsu@chromium.org>
Tested-by: Boleyn Su <boleynsu@chromium.org>
Auto-Submit: Boleyn Su <boleynsu@chromium.org>
diff --git a/sys-apps/baselayout-java/baselayout-java-0.1.0-r1.ebuild b/sys-apps/baselayout-java/baselayout-java-0.1.0-r2.ebuild
similarity index 83%
rename from sys-apps/baselayout-java/baselayout-java-0.1.0-r1.ebuild
rename to sys-apps/baselayout-java/baselayout-java-0.1.0-r2.ebuild
index 3f8e140..9537972 100644
--- a/sys-apps/baselayout-java/baselayout-java-0.1.0-r1.ebuild
+++ b/sys-apps/baselayout-java/baselayout-java-0.1.0-r2.ebuild
@@ -28,7 +28,7 @@
 	exeinto /etc/ca-certificates/update.d
 	newexe - java-cacerts <<-_EOF_
 		#!/bin/sh
-		exec trust extract --overwrite --format=java-cacerts --filter=ca-anchors --purpose server-auth "${EROOT}"/etc/ssl/certs/java/cacerts
+		exec trust extract --overwrite --format=java-cacerts --filter=ca-anchors --purpose server-auth "${EPREFIX}/etc/ssl/certs/java/cacerts"
 	_EOF_
 }
 
@@ -44,6 +44,6 @@
 	# so jdk ebuilds can create symlink to in into security directory
 	if [[ ! -f "${EROOT}"/etc/ssl/certs/java/cacerts ]]; then
 		einfo "Generating java cacerts file from system ca-certificates"
-		"${EROOT}"/etc/ca-certificates/update.d/java-cacerts || die
+		trust extract --overwrite --format=java-cacerts --filter=ca-anchors --purpose server-auth "${EROOT}/etc/ssl/certs/java/cacerts" || die
 	fi
 }