DeprecatedOutputFormatWrapper does not work well with PartitionTap

[wonlay]

When using DeprecatedOutputFormatWrapper with PartitionTap, the output won't be committed to the final location but discarded in the temporary directory.

There are two issues here:

1. TapOutputCollector used by PartitionTag is testing if the output format is a FileOutputFormat or not, after wrapped, it's not a FileOutputFormat anymore, the filenames won't be created.
2. The commit never happen when used in this case, the test for commit will always return false, since the real output format is writing to a different temp dir, and no intermedium commit to bridge them up.