fix a bug where copybit only renders in the first buffer when used with s/w GL
diff --git a/opengl/libagl/state.cpp b/opengl/libagl/state.cpp
index a00f779..a59b3b0 100644
--- a/opengl/libagl/state.cpp
+++ b/opengl/libagl/state.cpp
@@ -101,7 +101,7 @@
     c->copybits.blitEngine = NULL;
     c->copybits.minScale = 0;
     c->copybits.maxScale = 0;
-    c->copybits.drawSurfaceFd = -1;
+    c->copybits.drawSurfaceBuffer = 0;
 
 #ifdef LIBAGL_USE_GRALLOC_COPYBITS
     hw_module_t const* module;