Don't try and generate vbos for surfaces with no verts nor elements.

git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@5574 fc73d0e0-1445-4013-8a0c-d673dee63da5

engine/gl/gl_rsurf.c

@@ -78,7 +78,7 @@ static qboolean GL_BuildVBO(vbo_t *vbo, void *vdata, int vsize, void *edata, int
 	int s;
 	unsigned int vaostatic = 0;
 
-	if (!qglGenBuffersARB)
+	if (!qglGenBuffersARB || !vsize || !elementsize)
 		return false;
 
 	qglGenBuffersARB(1+(elementsize>0), vbos);