ref-manual: Updated CLASSOVERRIDE with a new example.

(From yocto-docs rev: 057e79672769eb1fbec87695a0084f42955f757d)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-variables.xml

@@ -2011,11 +2011,12 @@
          install my-extra-file ${D}${sysconfdir}
      }
                     </literallayout>
-                    Here is an example where "python-native" is added to
-                    <link linkend='var-DEPENDS'><filename>DEPENDS</filename></link>,
-                    but only when building for the build host:
+                    Here is an example where <filename>FOO</filename>
+                    is set to "native" when building for the build host, and
+                    to "other" when not building for the build host:
                     <literallayout class='monospaced'>
-     DEPENDS_append_class-native = " python-native"
+     FOO_class-native = "native"
+     FOO = "other"
                     </literallayout>
                     The underlying mechanism behind
                     <filename>CLASSOVERRIDE</filename> is simply that it is