GetFileType is meant to return the type of the given file by using os.Stat.
However, os.Stat doesn't work on Windows for Unix Sockets, causing an error to occur:
[2-Socket Test] unexpected error :
CreateFile C:\Users\Administrator\AppData\Local\Temp\test-get-filetype-2776877299\mt.sock:
The file cannot be accessed by the system.
This is a known issue and we're already using a workaround for this in
pkg/kubelet/util/util_windows.go.
This commit fixes this issue for GetFileType on Windows.
