[media] DocBook/media: fix syntax error

Missing varlistentry tags.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/v4l/vidioc-qbuf.xml

@@ -186,6 +186,8 @@ In that case the application should be able to safely reuse the buffer and
 continue streaming.
 	</para>
 	</listitem>
+      </varlistentry>
+      <varlistentry>
 	<term><errorcode>EPIPE</errorcode></term>
 	<listitem>
 	  <para><constant>VIDIOC_DQBUF</constant> returns this on an empty