Fix Sucessful to Successful typo in @return

[Tlapi]

Summary

Checklist

• [ x] Added changelog entry
• [ x] Ran unit tests (Check the README for instructions)

[Tlapi]

Why wasn't this merged into 6.5.1?

[jplukarski]

Why wasn't this merged into 6.5.1?

@Tlapi apologies for the oversight. We will merge it now to ensure that it gets out in our next release.