docs: fix html end/start tags

for more well-formed html

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/vmware-guest.html b/docs/vmware-guest.html
index 7faa315..1fe4a05 100644
--- a/docs/vmware-guest.html
+++ b/docs/vmware-guest.html
@@ -186,9 +186,11 @@
 OpenGL version string: 2.1 Mesa 8.0
 </pre>
 
+<p>
 If you don't see this, try setting this environment variable:
   <pre>
   export LIBGL_DEBUG=verbose</pre>
+<p>
 then rerun glxinfo and examine the output for error messages.
 </p>