greybus: remove excessive check in gb_connection_hd_cport_quiesce()

Function pointer "hd->driver->cport_quiesce" is already checked
at the beginning of gb_connection_hd_cport_quiesce(). Thus, the
second check can be removed.
Signed-off-by: Denis Efremov <efremov@linux.com>
Acked-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190925213656.8950-1-efremov@linux.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/greybus/connection.c

@@ -361,9 +361,6 @@ static int gb_connection_hd_cport_quiesce(struct gb_connection *connection)
 	if (connection->mode_switch)
 		peer_space += sizeof(struct gb_operation_msg_hdr);
 
-	if (!hd->driver->cport_quiesce)
-		return 0;
-
 	ret = hd->driver->cport_quiesce(hd, connection->hd_cport_id,
 					peer_space,
 					GB_CONNECTION_CPORT_QUIESCE_TIMEOUT);