Refactored fileSystem.LookUpInode.
Refactored fileSystem.LookUpInode.

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