Made non-dirty flushes work again.
Made non-dirty flushes work again.

kahing/gcsfuse,jacobsa/timeutil,BanzaiMan/gcsfuse,jacobsa/ratelimit,GoogleCloudPlatform/gcsfuse,BanzaiMan/gcsfuse,mbrukman/gcsfuse,GoogleCloudPlatform/gcsfuse,GoogleCloudPlatform/gcsfuse