[SPARK-6015] fix links to source code in Python API docs

[davies]

No description provided.

[SparkQA]

Test build #27962 has started for PR 4772 at commit 389f0c6.

• This patch merges cleanly.

[jkbradley]

LGTM, worked on my machine

[SparkQA]

Test build #27962 has finished for PR 4772 at commit 389f0c6.

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

[AmplabJenkins]

Test FAILed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/27962/
Test FAILed.

[SparkQA]

Test build #621 has started for PR 4772 at commit 389f0c6.

• This patch merges cleanly.

[SparkQA]

Test build #621 has finished for PR 4772 at commit 389f0c6.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[rxin]

Merging in master. Thanks!

[jkbradley]

@rxin Uh, this was meant to be a backport for branch-1.2. It was already fixed in master and branch-1.3 by [https://github.com//pull/4756]

[rxin]

Yup I meant 1.2... I accidentally also cherry picked it into 1.3, which is a noop.

[andrewor14]

Hey @davies can you close this since it's already merged?