net: marvell: prestera: remove reduntant code

Fixes the coverity warning 'EVALUATION_ORDER' violation. port is written
twice with the same value.
Signed-off-by: Sebin Sebastian <mailmesebin00@gmail.com>
Link: https://lore.kernel.org/r/20220801040731.34741-1-mailmesebin00@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/prestera/prestera_main.c

@@ -290,7 +290,7 @@ static int prestera_pcs_config(struct phylink_pcs *pcs,
 			       const unsigned long *advertising,
 			       bool permit_pause_to_mac)
 {
-	struct prestera_port *port = port = prestera_pcs_to_port(pcs);
+	struct prestera_port *port = prestera_pcs_to_port(pcs);
 	struct prestera_port_mac_config cfg_mac;
 	int err;