[SMALLFIX] Correct Javadoc in BlockStore.java

[tiancity-NJU]

change the BlockStore.java

[alluxio-bot]

Hi @halfmooon, thanks for your contribution!

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[alluxio-bot]

Automated checks report:

• Valid pull request title: FAIL
  • Pull request titles should either start with [SMALLFIX], [DOCFIX], or [ALLUXIO-####], see http://www.alluxio.org/docs/master/en/Contributing-to-Alluxio.html#submitting-code
• Commits associated with Github account: PASS

Please fix the reported issues and reply 'alluxio-bot, check this please' to re-run checks

[tiancity-NJU]

change the title from [SmallFix] to [SMALLFIX]

[AmplabJenkins]

Merged build finished. Test PASSed.

[AmplabJenkins]

Test PASSed.
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Test PASSed.

[tiancity-NJU]

@alluxio-bot please check my license,thanks

[alluxio-bot]

You did it @halfmooon!

Thank you for signing the Contribution License Agreement.

[alluxio-bot]

Automated checks report:

• Valid pull request title: PASS
• Commits associated with Github account: PASS

All checks passed!