Comment out more duplicate sections

Upstream has removed the duplicated sections in r11422.
The translation note in usage.xml is no longer necessary.

chapter07/udev.xml

@@ -248,7 +248,7 @@
 
     </sect3>
 
-	<sect3 id="ch-hotplug-device">
+	<sect3>
       <title>处理热插拔/动态设备</title>
 
       <!--para>When you plug in a device, such as a Universal Serial Bus (USB) MP3

chapter07/usage.xml

@@ -322,13 +322,17 @@ EOF</userinput></screen>
       protocols, filesystems and NLS support on demand.</para>
 
     </sect3>
--->
 
-     <note><title>译注</title>
-          <para>原文中这里有一小节与之前的
-              <xref linkend="ch-hotplug-device"/> 重复，这里删去了。
-          </para>
-      </note>
+    <sect3>
+      <title>Handling Hotpluggable/Dynamic Devices</title>
+
+      <para>When you plug in a device, such as a Universal Serial Bus (USB) MP3
+      player, the kernel recognizes that the device is now connected and
+      generates a uevent. This uevent is then handled by
+      <command>udevd</command> as described above.</para>
+
+    </sect3>
+-->
   </sect2>
 
   <sect2 id="ch-scripts-clock">