Merge pull request #12953 from jerrywgz/fix_prelu

add error_info for prelu_op

paddle/fluid/operators/prelu_op.cc

@@ -26,10 +26,13 @@ class PReluOp : public framework::OperatorWithKernel {
     std::string mode = ctx->Attrs().Get<std::string>("mode");
 
     auto x_dim = ctx->GetInputDim("X");
-    PADDLE_ENFORCE(ctx->HasInput("X"), "Input(X) should not be null");
-    PADDLE_ENFORCE(ctx->HasInput("Alpha"), "Input(Alpha) should not be null");
+    PADDLE_ENFORCE(ctx->HasInput("X"),
+                   "Input(X) of PreluOp should not be null");
+    PADDLE_ENFORCE(ctx->HasInput("Alpha"),
+                   "Input(Alpha) of PreluOp should not be null");
 
-    PADDLE_ENFORCE(ctx->HasOutput("Out"), "Output(Out) should not be null");
+    PADDLE_ENFORCE(ctx->HasOutput("Out"),
+                   "Output(Out) of PreluOp should not be null");
     if (mode == "all") {
       PADDLE_ENFORCE(product(ctx->GetInputDim("Alpha")) == 1,
                      "For mode 'all', size of weight Alpha must be one.");