remove mentionings of devfs in documentation

Now that devfs is removed, there's no longer any need to document how to
do this or that with devfs.

This patch includes some improvements by Joe Perches.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/DocBook/usb.tmpl b/Documentation/DocBook/usb.tmpl
index 3608472..fbc72d4 100644
--- a/Documentation/DocBook/usb.tmpl
+++ b/Documentation/DocBook/usb.tmpl
@@ -314,8 +314,7 @@
 	<emphasis>usbdevfs</emphasis> although it wasn't solving what
 	<emphasis>devfs</emphasis> was.
 	Every USB device will appear in usbfs, regardless of whether or
-	not it has a kernel driver; but only devices with kernel drivers
-	show up in devfs.
+	not it has a kernel driver.
 	</para>
 
 	<sect1>