docbook: fix v4l fatal filename error

docproc: /var/linsrc/lin2627-rc2/drivers/media/video/videodev.c: No such file or directory
make[1]: *** [Documentation/DocBook/videobook.xml] Error 1
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
cc: mchehab@infradead.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/DocBook/videobook.tmpl

@@ -1648,7 +1648,7 @@ static struct video_buffer capture_fb;
 
   <chapter id="pubfunctions">
      <title>Public Functions Provided</title>
-!Edrivers/media/video/videodev.c
+!Edrivers/media/video/v4l2-dev.c
   </chapter>
 
 </book>