fix(475): Fixed an test failure in Unix platform

Author: vigneshmoha

System.IO.Abstractions.TestingHelpers.Tests/MockDirectoryTests.cs

@@ -794,8 +794,8 @@ public void MockDirectory_GetFiles_Returns_Files_WithRelativePath()
             // arrange
             var fileSystem = new MockFileSystem(new Dictionary<string, MockFileData>());
 
-            const string dir = @"C:\foo";
-            fileSystem.Directory.SetCurrentDirectory(dir);
+            string directory = XFS.Path(@"C:\foo");
+            fileSystem.Directory.SetCurrentDirectory(directory);
             fileSystem.AddFile($@"C:\test.txt", new MockFileData("Some ASCII text."));
 
             Assert.AreEqual(fileSystem.Directory.GetFiles(@"C:\").Length, 1); // Assert with absolute path