Simplify code: decrease one level of indentation

[alexandear]

Description

This PR simplifies RootApp.Run function by removing else clause.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Version of Golang used when building/testing:

• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20

How Has This Been Tested?

Run go test ./...

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[codecov]

Codecov Report

Patch coverage: 60.82474% and no project coverage change.

Comparison is base (97cd18b) 76.54039% compared to head (c02f74e) 76.54039%.

Additional details and impacted files

@@              Coverage Diff              @@
##              master        #659   +/-   ##
=============================================
  Coverage   76.54039%   76.54039%           
=============================================
  Files              8           8           
  Lines           2191        2191           
=============================================
  Hits            1677        1677           
  Misses           378         378           
  Partials         136         136           

Impacted Files	Coverage Δ
cmd/mockery.go	62.16216% <60.82474%> (ø)

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[LandonTClipp]

Thank you!