More error checks

Change-Id: Id2b9ab7a76bbdf2ed745f5e36e552dc9b101982f
diff --git a/libs/rs/rsProgramVertex.h b/libs/rs/rsProgramVertex.h
index 824edbb..2a5c863 100644
--- a/libs/rs/rsProgramVertex.h
+++ b/libs/rs/rsProgramVertex.h
@@ -40,7 +40,7 @@
 
     void transformToScreen(Context *, float *v4out, const float *v3in) const;
 
-    virtual void createShader();
+    virtual void createShader(Context *);
     virtual void loadShader(Context *);
     virtual void init(Context *);