More release note fixes.

This is what I get for being so hasty for release notes.
Signed-off-by: Austin Seipp <austin@well-typed.com>

docs/users_guide/7.8.1-notes.xml

@@ -184,12 +184,6 @@
                 <literal>-jN</literal> in order to compile
                 <replaceable>N</replaceable> modules in parallel.
            </para>
-
-            <para>
-                Note that if you wish for GHC to use multiple cores,
-                you will need to use the <literal>+RTS -N</literal>
-                flag.
-           </para>
        </listitem>
    </itemizedlist>
   </sect2>

docs/users_guide/flags.xml

@@ -2985,7 +2985,7 @@
         <tbody>
           <row>
             <entry><option>-j <replaceable>N</replaceable></option></entry>
-            <entry>When compiling with <literal>--make</literal>, compile <replaceable>N</replaceable></entry>
+            <entry>When compiling with <literal>--make</literal>, compile <replaceable>N</replaceable> modules in parallel.</entry>
             <entry>dynamic</entry>
             <entry>-</entry>
           </row>