docs: get rid of duplicated description from sourcetree.html

Fixes: 438086efb17 (docs: sourcetree.html misc updates)
Signed-off-by: Mun Gwan-gyeong <elongbug@gmail.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/docs/sourcetree.html b/docs/sourcetree.html
index aee3321..7013f65 100644
--- a/docs/sourcetree.html
+++ b/docs/sourcetree.html
@@ -140,7 +140,6 @@
        <li><b>clover</b> - OpenCL state tracker
        <li><b>dri</b> - Meta state tracker for DRI drivers
        <li><b>glx</b> - Meta state tracker for GLX
-       <li><b>vdpau</b> - VDPAU state tracker
        <li><b>wgl</b> - Windows WGL state tracker
        <li><b>xa</b> - XA state tracker
        <li><b>xvmc</b> - XvMC state tracker