meta-openpower: prep for new override syntax

Change-Id: I5ca16c6fa7bc616bfa9bc41c4f86d32fd92b0287
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-openpower/recipes-phosphor/dump/phosphor-debug-errors-native.bbappend b/meta-openpower/recipes-phosphor/dump/phosphor-debug-errors-native.bbappend
index 72d991c..4fc41d0 100644
--- a/meta-openpower/recipes-phosphor/dump/phosphor-debug-errors-native.bbappend
+++ b/meta-openpower/recipes-phosphor/dump/phosphor-debug-errors-native.bbappend
@@ -1 +1 @@
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"