[SPARK-11388][Build]Fix self closing tags.

[hvanhovell]

Java 8 javadoc does not like self closing tags: <p/>, <br/>, ...

This PR fixes those.

[vanzin]

I thought we disabled doclint in java 8, but apparently we just disable one check... :-/

ok to test

[srowen]

I would just remove this entirely. Now, the tag isn't closed. The newline isn't important here anyhow. Feel free to clean up any other javadoc warnings you encounter.

[vanzin]

javadoc enforces a broken version of HTML where you don't need to close certain tags like p. It's a little annoying, but you still need the HTML to format the docs nicely.

[vanzin]

ok to test

[SparkQA]

Test build #44581 has finished for PR 9339 at commit 7d80528.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[hvanhovell]

Hmmm, test fails with the following beautiful error:

[error] (core/test:test) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 4809 s, completed Oct 29, 2015 2:32:35 AM

Retesting.

[hvanhovell]

jenkins retest this please

[vanzin]

probably unrelated. this change shouldn't really cause any test failures. retest this please

[SparkQA]

Test build #44588 has finished for PR 9339 at commit 7d80528.

• This patch fails PySpark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[vanzin]

That's a known flaky pyspark test. Change LGTM.

[srowen]

merged to master