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>

pkg/fs/fs_windows_test.go

@@ -18,7 +18,9 @@ func TestGetFSTypeOfKnownDrive(t *testing.T) {
 }
 
 func TestGetFSTypeOfInvalidPath(t *testing.T) {
-	_, err := GetFileSystemType("7:\\")
+	// [filepath.VolumeName] doesn't mandate that the drive letters matches [a-zA-Z].
+	// Instead, use non-character drive.
+	_, err := GetFileSystemType(`No:\`)
 	if !errors.Is(err, ErrInvalidPath) {
 		t.Fatalf("Expected `ErrInvalidPath`, got %v", err)
 	}