fix the build issue on gpu mode for win

test=develop

Author: wopeizl

paddle/fluid/framework/ir/graph.h

@@ -141,7 +141,8 @@ class Graph {
   ir::Node *CreateControlDepVar() {
     // TODO(panyx0718): control var name should be really unique.
     const std::string name = string::Sprintf(
-        "%s@%llu", ir::Node::kControlDepVarName, node_set_.size());
+        "%s@%llu", static_cast<const char *>(ir::Node::kControlDepVarName),
+        node_set_.size());
     auto *x = AddNode(new ir::Node(name, ir::Node::Type::kVariable));
     x->SetId(num_node_created_++);
     return x;