Test hh length.

test/printf-test.cc

@@ -331,7 +331,7 @@ void TestLength(const char *length_spec) {
 TEST(PrintfTest, Length) {
   EXPECT_EQ("-128", sprintf_int<signed char>("%hhd", SCHAR_MAX + 1));
   EXPECT_EQ("128", sprintf_int<signed char>("%hhu", SCHAR_MAX + 1));
-  //TestLength<signed char>("hh");
+  TestLength<signed char>("hh");
   //TestLength<unsigned char>("hh");
   //TestLength<short>("h");
   //TestLength<unsigned short>("h");