ref-manual: Edits to PF variable.

(From yocto-docs rev: 3bab86533ea801231e6c2ef54b1f55f5a2ac3d2e)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-variables.xml

@@ -2526,7 +2526,7 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
                     <filename>bash-4.2-r1/</filename>).
                     This variable is comprised of the following:
                     <literallayout class='monospaced'>
-     ${PN}-${EXTENDPE}${PV}-${PR}
+     ${<link linkend='var-PN'>PN</link>}-${<link linkend='var-EXTENDPE'>EXTENDPE</link>}${<link linkend='var-PV'>PV</link>}-${<link linkend='var-PR'>PR</link>}
                     </literallayout></para>
             </glossdef>
         </glossentry>