meta-phosphor: prep for new override syntax

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I588025b614416c43aa2d053765ab53bacf890cb5
diff --git a/meta-phosphor/recipes-devtools/i2c-tools/i2c-tools_%.bbappend b/meta-phosphor/recipes-devtools/i2c-tools/i2c-tools_%.bbappend
index 349888e..e08b159 100644
--- a/meta-phosphor/recipes-devtools/i2c-tools/i2c-tools_%.bbappend
+++ b/meta-phosphor/recipes-devtools/i2c-tools/i2c-tools_%.bbappend
@@ -1,3 +1,3 @@
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
 SRC_URI =+ "file://0001-4-byte-read-support-466.patch \
             file://0001-i2cget-Add-support-for-i2c-block-data.patch"