Wrong count assertion in taxonomy.test

Issue Summary

Problem/Motivation

There is a wrong assertion in taxonomy.test that always evaluates to TRUE.

This is always TRUE. It should at least be count($terms4) == 4. However, it would be better to replace the assertion with assertEqual(): $this->assertEqual(count($terms4), 4, ...).

Proposed resolution

• Change the mentioned line of code to assertEqual() and fix the count().
• Look for other places in the file that could be done using assertEqual() instead of assertTrue() to simplify the code.

Remaining tasks

This should only be done once both #1160566: entity_load() is actually entity_load_multiple() and #1195254: Taxonomy test cleanup have been commited (the the second already has been commited to 8.x, only needs to be commited to 7.x, the first will not be backported) because both patches currently touch that line or come too close so that it will need a re-roll.