Remove an erroneous file in gcc added by the fixincludes process

was r11649.

chapter06/gcc.xml

@@ -165,9 +165,10 @@ su nobody -s /bin/bash -c "PATH=$PATH make -k check"</userinput></screen>
 	  这些测试也会失败。
     </para></note-->
 
-    <para>安装该软件包：</para>
+    <para>安装该软件包，并移除一个不需要的目录：</para>
 
-<screen><userinput remap="install">make install</userinput></screen>
+<screen><userinput remap="install">make installi
+rm -rf /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/include-fixed/bits/</userinput></screen>
 
     <para>创建一个 <ulink
     url="https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s09.html">FHS</ulink>