Added missing '\n' in visual shader expression node code generation

(cherry picked from commit 6e1187ad2f378a5e72021056839c728414e29e37)

scene/resources/visual_shader.cpp

@@ -2644,7 +2644,7 @@ String VisualShaderNodeExpression::generate_code(Shader::Mode p_mode, VisualShad
 	code += output_initializer;
 	code += "\t{";
 	code += _expression;
-	code += "\n\t}";
+	code += "\n\t}\n";
 
 	return code;
 }