[media] DocBook/demux.xml: Remove generic errors

Remove generic errors from ioctl() descriptions. For other ioctl's,
there's no generic section. So, just keep whatever is there.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/media/v4l/gen-errors.xml b/Documentation/DocBook/media/v4l/gen-errors.xml
index d970f08..c981879 100644
--- a/Documentation/DocBook/media/v4l/gen-errors.xml
+++ b/Documentation/DocBook/media/v4l/gen-errors.xml
@@ -48,6 +48,11 @@
 	       that this request would overcommit the usb bandwidth reserved
 	       for periodic transfers (up to 80% of the USB bandwidth).</entry>
       </row>
+      <row>
+	<entry>EWOULDBLOCK</entry>
+	<entry>Operation would block. Used when the ioctl would need to wait
+	       for an event, but the device was opened in non-blocking mode.</entry>
+      </row>
     </tbody>
   </tgroup>
 </table>