mlxsw: spectrum_router: Avoid uninitialized symbol errors

Suppress the following smatch errors. None of these are actually
possible with current code paths.

drivers/net/ethernet/mellanox/mlxsw//spectrum_router.c:1220
mlxsw_sp_ipip_entry_find_decap() error: uninitialized symbol 'saddrp'.
drivers/net/ethernet/mellanox/mlxsw//spectrum_router.c:1220
mlxsw_sp_ipip_entry_find_decap() error: uninitialized symbol
'saddr_len'.
drivers/net/ethernet/mellanox/mlxsw//spectrum_router.c:1221
mlxsw_sp_ipip_entry_find_decap() error: uninitialized symbol
'saddr_prefix_len'.

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:1390
mlxsw_sp_netdevice_ipip_ol_reg_event() error: uninitialized symbol
'ipipt'.

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3255
mlxsw_sp_nexthop_group_update() error: uninitialized symbol 'err'.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -1212,7 +1212,7 @@ mlxsw_sp_ipip_entry_find_decap(struct mlxsw_sp *mlxsw_sp,
 		saddr_len = 4;
 		saddr_prefix_len = 32;
 		break;
-	case MLXSW_SP_L3_PROTO_IPV6:
+	default:
 		WARN_ON(1);
 		return NULL;
 	}
@@ -1380,9 +1380,9 @@ static bool mlxsw_sp_netdevice_ipip_can_offload(struct mlxsw_sp *mlxsw_sp,
 static int mlxsw_sp_netdevice_ipip_ol_reg_event(struct mlxsw_sp *mlxsw_sp,
 						struct net_device *ol_dev)
 {
+	enum mlxsw_sp_ipip_type ipipt = MLXSW_SP_IPIP_TYPE_MAX;
 	struct mlxsw_sp_ipip_entry *ipip_entry;
 	enum mlxsw_sp_l3proto ul_proto;
-	enum mlxsw_sp_ipip_type ipipt;
 	union mlxsw_sp_l3addr saddr;
 	u32 ul_tb_id;
 
@@ -3231,7 +3231,6 @@ mlxsw_sp_nexthop_group_update(struct mlxsw_sp *mlxsw_sp,
 	u32 adj_index = nh_grp->adj_index; /* base */
 	struct mlxsw_sp_nexthop *nh;
 	int i;
-	int err;
 
 	for (i = 0; i < nh_grp->count; i++) {
 		nh = &nh_grp->nexthops[i];
@@ -3242,6 +3241,8 @@ mlxsw_sp_nexthop_group_update(struct mlxsw_sp *mlxsw_sp,
 		}
 
 		if (nh->update || reallocate) {
+			int err = 0;
+
 			switch (nh->type) {
 			case MLXSW_SP_NEXTHOP_TYPE_ETH:
 				err = mlxsw_sp_nexthop_update