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The flight from Sweden to Finland is an internal Schengen flight, so you do not go through immigration.
You will likely pass through customs, but as you travel from one EU-Schengen country to an other you can just walk through the EU line if they have one or Nothing to declare if that seems the only or better option, unless you want to ask customs people questions.
Do leave enough time for security, internal Schengen flights have the same security as intercontinental flights.
Your nationality does not matter but the airline may want to check you are in the Schengen area legally, some airlines want you to get your boarding pass stamped with 'visa checked', which may also take some more time.