SUNRPC: Remove dead code from xs_tcp_tls_setup_socket()

xs_tcp_tls_finish_connecting() already marks the upper xprt
connected, so the same code in xs_tcp_tls_setup_socket() is
never executed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>