native frameworks: 64-bit compile issues

- Fix format (print/scanf)
- Suppress unused argument warning messages (bonus)

Change-Id: I05c7724d2aba6da1e82a86000e11f3a8fef4e728
diff --git a/opengl/libagl/vertex.cpp b/opengl/libagl/vertex.cpp
index dad04d6..9aacdb3 100644
--- a/opengl/libagl/vertex.cpp
+++ b/opengl/libagl/vertex.cpp
@@ -41,7 +41,7 @@
     c->currentNormal.z = 0x10000;
 }
 
-void ogles_uninit_vertex(ogles_context_t* c)
+void ogles_uninit_vertex(ogles_context_t* /*c*/)
 {
 }