Don’t overwrite file when formatting if not needed

[marcelofabri]

Fixes #2249

@petterikamppuririchie can you please check if this fixes the issue?

[SwiftLintBot]

	12 Messages
📖	Linting Aerial with this PR took 0.38s vs 0.37s on master (2% slower)
📖	Linting Alamofire with this PR took 3.37s vs 3.13s on master (7% slower)
📖	Linting Firefox with this PR took 13.31s vs 11.84s on master (12% slower)
📖	Linting Kickstarter with this PR took 21.16s vs 17.36s on master (21% slower)
📖	Linting Moya with this PR took 2.29s vs 1.95s on master (17% slower)
📖	Linting Nimble with this PR took 2.0s vs 1.59s on master (25% slower)
📖	Linting Quick with this PR took 0.54s vs 0.51s on master (5% slower)
📖	Linting Realm with this PR took 3.89s vs 3.19s on master (21% slower)
📖	Linting SourceKitten with this PR took 1.13s vs 1.0s on master (12% slower)
📖	Linting Sourcery with this PR took 5.25s vs 4.55s on master (15% slower)
📖	Linting Swift with this PR took 31.26s vs 28.01s on master (11% slower)
📖	Linting WordPress with this PR took 15.46s vs 15.07s on master (2% slower)

Generated by 🚫 Danger

[codecov-io]

Codecov Report

Merging #2257 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #2257      +/-   ##
==========================================
- Coverage   92.09%   92.08%   -0.02%     
==========================================
  Files         286      286              
  Lines       14530    14532       +2     
==========================================
  Hits        13382    13382              
- Misses       1148     1150       +2

Impacted Files	Coverage Δ
Source/swiftlint/Commands/AutoCorrectCommand.swift	0% <0%> (ø)	⬆️
Source/SwiftLintFramework/Models/Linter.swift	82.01% <0%> (-3.7%)	⬇️

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[petterikamppuririchie]

It sure does! Thanks for the quick fix! 👍