HDDS-15451. Fix broken pip install syntax in TestTools.md

[amaliujia]

What changes were proposed in this pull request?

Summary

Fix broken pip install syntax in Blockade testing docs

Description

The Blockade section in hadoop-hdds/docs/content/tools/TestTools.md shows an invalid pip install command:

pip install pytest==2.8.7,blockade

The comma makes pip treat pytest==2.8.7,blockade as a single package name, so the command fails for anyone following the docs.

Fix: use space-separated package names:

pip install pytest==2.8.7 blockade

What is the link to the Apache JIRA

HDDS-15451

How was this patch tested?

Tested by hugo serve.

[sreejasahithi]

@amaliujia could you please create a jira for this PR and mention the jira ID in the PR title as well as in the commit message.

Example: #7806

[amaliujia]

@sreejasahithi thank you and done.

[adoroszlai]

Thanks @amaliujia for checking these docs.

[adoroszlai]

I think it's in tests/blockade.

ozone/hadoop-ozone/dist/dev-support/bin/dist-layout-stitching

Lines 112 to 113 in ba78ed8

	# fault injection tests
	run cp -r "${ROOT}/hadoop-ozone/fault-injection-test/network-tests/src/test/blockade" tests

Suggested change

	cd blockade
	cd tests/blockade

Also appears in the sentence above:

ozone/hadoop-hdds/docs/content/tools/TestTools.md

Line 59 in ba78ed8

Blockade tests are implemented with the help of tests and can be started from the `./blockade` directory of the distribution.

Also please consider improving that sentence, I don't think "Blockade tests are implemented with the help of tests" is meaningful.

[amaliujia]

comments addressed.