Bug: Close hvsock handle on listen error; fix tests (#310)

* Bug: Close hvsock handle on listen error; fix tests

Close the socket created in
`github.com/Microsoft/go-winio/pkg/ListenHvsock` if either the `Bind` or
`Listen` calls fail.

Go changed `filepath.VolumeName` code, resulting in different behavior in
`github.com/Microsoft/go-winio/pkg/fs.GetFileSystemType`.
Update test accordingly.
Also add more debug logs to `pkg\fs\resolve_test.go`.

Also, move add skip for fuzzing on WS2019 or older to `FuzzHvSockRxTx`
code directly, instead of in ci.yml.

See: https://go-review.googlesource.com/c/go/+/540277

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

* PR: unskip TestResolvePath

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

---------

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

hvsock.go

@@ -196,10 +196,18 @@ func newHVSocket() (*win32File, error) {
 // ListenHvsock listens for connections on the specified hvsock address.
 func ListenHvsock(addr *HvsockAddr) (_ *HvsockListener, err error) {
 	l := &HvsockListener{addr: *addr}
-	sock, err := newHVSocket()
+
+	var sock *win32File
+	sock, err = newHVSocket()
 	if err != nil {
 		return nil, l.opErr("listen", err)
 	}
+	defer func() {
+		if err != nil {
+			_ = sock.Close()
+		}
+	}()
+
 	sa := addr.raw()
 	err = socket.Bind(sock.handle, &sa)
 	if err != nil {