The echo server shouldn't close the connection when there's an error on
write. Instead simply echo the error message and allow the other side to
close the connection.
Also do a partial revert of 4d905fb where after_shutdown was removed.
Fixes: 4d905fb "test: close stream immediately on error"
Signed-off-by: Trevor Norris <trev.norris@gmail.com>
Signed-off-by: Saúl Ibarra Corretgé <saghul@gmail.com>