poky: fix remove/append override syntax in comment

The examples for changing WARN_QA and ERROR_QA still use the old
('_'-style) override syntax.

(From meta-yocto rev: 303e49733300e7e440ee4e8d9cd6eec67143aa91)

Signed-off-by: Enrico Jörns <ejo@pengutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-poky/conf/distro/poky.conf

@@ -56,8 +56,8 @@ INHERIT += "poky-sanity"
 # QA check settings - a little stricter than the OE-Core defaults
 # (none currently necessary as we now match OE-Core)
 #WARN_TO_ERROR_QA = "X"
-#WARN_QA_remove = "${WARN_TO_ERROR_QA}"
-#ERROR_QA_append = " ${WARN_TO_ERROR_QA}"
+#WARN_QA:remove = "${WARN_TO_ERROR_QA}"
+#ERROR_QA:append = " ${WARN_TO_ERROR_QA}"
 
 require conf/distro/include/poky-world-exclude.inc
 require conf/distro/include/no-static-libs.inc