ssh: Recreate connection on retries in setupProxy

The previous fix was not working as expected, as the ssh go code will
close the underlying connection when there's a failure.
This was causing the retries for CreateBastion() to fail, as after the
first failure it would try to use a closed connection.

This commit recreates the connection each time before calling
CreateBastion() to fix this. This also simplifies the code.

pkg/sshclient/ssh_forwarder.go

@@ -166,12 +166,11 @@ func setupProxy(ctx context.Context, socketURI *url.URL, dest *url.URL, identity
 		return conn, err
 	}
 
-	conn, err := initialConnection(ctx, connectFunc)
-	if err != nil {
-		return &SSHForward{}, err
-	}
-
 	createBastion := func() (*Bastion, error) {
+		conn, err := connectFunc(ctx, nil)
+		if err != nil {
+			return nil, err
+		}
 		return CreateBastion(dest, passphrase, identity, conn, connectFunc)
 	}
 	bastion, err := retry(ctx, createBastion, "Waiting for sshd")
@@ -215,13 +214,6 @@ loop:
 	return returnVal, fmt.Errorf("timeout: %w", err)
 }
 
-func initialConnection(ctx context.Context, connectFunc ConnectCallback) (net.Conn, error) {
-	retryFunc := func() (net.Conn, error) {
-		return connectFunc(ctx, nil)
-	}
-	return retry(ctx, retryFunc, "Waiting for sshd socket")
-}
-
 func acceptConnection(ctx context.Context, listener net.Listener, bastion *Bastion, socketURI *url.URL) error {
 	con, err := listener.Accept()
 	if err != nil {