Fix small typo in tests (#113)

* Update LoggingTest.swift

* Apply suggestions from code review

Author: FranzBusch

Tests/LoggingTests/LoggingTest.swift

@@ -29,10 +29,10 @@ class LoggingTest: XCTestCase {
         var logger = Logger(label: "test")
         logger.logLevel = .info
         logger.log(level: .debug, {
-            XCTFail("trace should not be called")
-            return "trace"
+            XCTFail("debug should not be called")
+            return "debug"
         }())
-        logger.debug({
+        logger.trace({
             XCTFail("trace should not be called")
             return "trace"
         }())