[MINOR] HoodieFileScanRDD could print null path

[boneanxs]

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What is the purpose of the pull request

Fix this:

22/03/17 14:58:13 INFO HoodieFileScanRDD: Reading File null

Brief change log

(for example:)

• Modify AnnotationLocation checkstyle rule in checkstyle.xml

Verify this pull request

(Please pick either of the following options)

This pull request is a trivial rework / code cleanup without any test coverage.

(or)

This pull request is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end.
• Added HoodieClientWriteTest to verify the change.
• Manually verified the change by running a job locally.

Committer checklist

• Has a corresponding JIRA in PR title & commit

• Commit message is descriptive of the change

• CI is green

• Necessary doc changes done or have another open PR

• For large changes, please consider breaking it into sub-tasks under an umbrella JIRA.

[hudi-bot]

CI report:

• 5bbdbc5 Azure: SUCCESS

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build

[yihua]

LGTM