changed label 'none' to usbdevfs so it's easier to figure out to see

what it is from a 'mount' output


git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@1224 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter08/fstab.xml

@@ -36,7 +36,7 @@ devpts:</para>
 
 <para>Another example is a line to use if you intend to use USB
 devices:</para>
-<para><screen>none		/proc/bus/usb	usbdevfs defaults        0 0</screen></para>
+<para><screen>usbdevfs		/proc/bus/usb	usbdevfs defaults        0 0</screen></para>
 
 <para>Both of these options will only work if you have the relevant
 support compiled into your kernel.</para>