ref-manual: Edits to buildhistory class.

(From yocto-docs rev: 8046633f00b376db502db98f78c772e94622fb6e)

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

documentation/ref-manual/ref-classes.xml

@@ -301,7 +301,7 @@
     <title><filename>buildhistory.bbclass</filename></title>
 
     <para>
-        The Build History (<filename>buildhistory</filename>) class records a
+        The <filename>buildhistory</filename> class records a
         history of build output metadata, which can be used to detect possible
         regressions as well as used for analysis of the build output.
         For more information on using Build History, see the