Improve test to call enum in another assembly

- Now enum type is actually used in a local variable and not just the value.

Author: josesimoes

MetadataProcessor.Tests/TestNFApp/TestEnumInAnotherAssembly.cs

@@ -11,10 +11,11 @@ public void CallTestEnumInAnotherAssembly()
         {
             // This test checks if MDP can minimize the assembly using an enum that is defined in another assembly
             // and the class calling it is in a different assembly BUT in the same namespace.
-            var ioException = new IOException(
+            IOException.IOExceptionErrorCode dummyEnum = IOException.IOExceptionErrorCode.DirectoryNotFound;
+
+            _ = new IOException(
                     string.Empty,
-                    (int)IOException.IOExceptionErrorCode.DirectoryNotFound);
+                    (int)dummyEnum);
         }
     }
-
 }