remove duplicated code

Author: bigplaice

src/backend/parser/parse_param.c

@@ -464,11 +464,6 @@ ParseParamVariable(Node *arg)
 		result = (Node *) ((ArrayCoerceExpr *)arg)->arg;
 		return ParseParamVariable(result);
 	}
-	else if (IsA(arg, ArrayCoerceExpr))
-	{
-		result = (Node *) ((ArrayCoerceExpr *)arg)->arg;
-		return ParseParamVariable(result);
-	}
 
 	return result;
 }