meta-quanta: runbmc-nuvoton: pid: fix build error of pid recipe

Change-Id: Iacb6656114492542b02e01bfe366ff444091e314
Signed-off-by: Tim Lee <timlee660101@gmail.com>
diff --git a/meta-runbmc-nuvoton/recipes-phosphor/fans/phosphor-pid-control_%.bbappend b/meta-runbmc-nuvoton/recipes-phosphor/fans/phosphor-pid-control_%.bbappend
index ead72a1..5d7e0f9 100644
--- a/meta-runbmc-nuvoton/recipes-phosphor/fans/phosphor-pid-control_%.bbappend
+++ b/meta-runbmc-nuvoton/recipes-phosphor/fans/phosphor-pid-control_%.bbappend
@@ -1,4 +1,4 @@
-FILESEXTRAPATHS_prepend_runbmc-nuvoton += "${THISDIR}/${PN}:"
+FILESEXTRAPATHS_prepend_runbmc-nuvoton := "${THISDIR}/${PN}:"
 
 SRC_URI_append_runbmc-nuvoton = " file://config-runbmc-nuvoton.json"
 SRC_URI_append_runbmc-nuvoton = " file://fan-full-speed.sh"