java-utils-2.eclass: select java-config binary, prefer java-config over java-config-2

This prepares the eclass for the transition from /usr/bin/java-config-2
to /usr/bin/java-config.

Starting with dev-java/java-config-2.3.3, the java-config utility is
installed as java-config and the java-config-2 compatibility symlink
will only be installed if the 'compat' USE flag is enabled (currently
the default).

Signed-off-by: Florian Schmaus <flow@gentoo.org>

eclass/java-utils-2.eclass

@@ -2723,7 +2723,13 @@ java-pkg_build-vm-from-handle() {
 	fi
 
 	for vm in ${JAVA_PKG_WANT_BUILD_VM}; do
-		if java-config-2 --select-vm=${vm} 2>/dev/null; then
+		local java_config
+		for java_config in java-config{,-2}; do
+			type -p ${java_config} >/dev/null && break
+		done
+		[[ -z ${java_config} ]] && die "No java-config binary in PATH"
+
+		if ${java_config} --select-vm=${vm} 2>/dev/null; then
 			echo ${vm}
 			return 0
 		fi