only use the latest version variable for inplace strategy (#16736)

* bug-fix, test=develop

* tweak code, test=develop

paddle/fluid/framework/details/inplace_op_pass.cc

@@ -305,6 +305,12 @@ void InplacePass::TryInplaceOpInputOutput(ir::Node* op,
 
     VLOG(4) << "Try to inplace " << in_var_name << " with " << out_var_name;
 
+    if (var_nodes_[in_var_name].back() != in_node) {
+      VLOG(4) << "SKIP since " << in_var_name
+              << " is also used as output by other ops";
+      continue;
+    }
+
     bool can_replace = true;
     if (in_var_name == out_var_name) {
       can_replace = false;