Fix the "IO error" in auto_roll_logger_test

Summary:

I missed InitTestDb() in one of my tess. InitTestDb() initializes the test directory, without which the test will throw IO error.

This problem didn't occur before because I've already run the tests before so the test directory is already there.

Test Plan:

Reviewers: dhruba

CC:

Task ID: #

Blame Rev:

Makefile

@@ -55,8 +55,10 @@ TESTS = \
 	version_set_test \
 	reduce_levels_test \
 	write_batch_test \
+	auto_roll_logger_test \
 	filelock_test
 
+
 TOOLS = \
 	manifest_dump \
         sst_dump \

util/auto_roll_logger_test.cc

@@ -119,6 +119,7 @@ uint64_t AutoRollLoggerTest::RollLogFileByTimeTest(
 }
 
 TEST(AutoRollLoggerTest, RollLogFileBySize) {
+    InitTestDb();
     size_t log_max_size = 1024 * 5;
 
     AutoRollLogger* logger = new AutoRollLogger(