Confused the type checker

Author: grynspan

Tests/TestingTests/AttachmentTests.swift

@@ -104,7 +104,7 @@ struct AttachmentTests {
     // Return the list of COM ports that are NOT configured (and so will fail
     // to open for writing.)
     (0...9).lazy
-      .flatMap { ["COM\($0)", "LPT\($0)"] }
+      .map { "COM\($0)" }
       .filter { !PathFileExistsA($0) }
   }()
 #else