Fix bug: false positive warning for typed function calls

[nunnatsa]

Description

When calling a function that return a type in the async assertion (eventually/constantly) body, if this type is a function, the linter fails to recognize it and fire a warning.

This PR fixes this bug, by checking the underline types.

Fixes #91

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• [x] Added test case and related test data
• [ ] Update the functional test

Checklist:

• [x] I have performed a self-review of my own code
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules
• [X] I ran golangci-lint

@nunnatsa

[nunnatsa]

@pohly, would you mind to take a look at this fix?

[github-actions[bot]]

Pull Request Test Coverage Report for Build 5391259784

• 8 of 8 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.08%) to 84.669%

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Totals
Change from base Build 5391215987:	0.08%
Covered Lines:	845
Relevant Lines:	998

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💛 - Coveralls