net: fman: memac: Uninitialized variable on error path

The "fixed_link" is only allocated sometimes but it's freed
unconditionally in the error handling.  Set it to NULL so we don't free
uninitialized data.

Fixes: 9ea4742a ("net: fman: Configure fixed link in memac_initialization")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/Ywd2X6gdKmTfYBxD@kiliSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/fman/mac.c

@@ -389,7 +389,7 @@ static int memac_initialization(struct mac_device *mac_dev,
 {
 	int			 err;
 	struct fman_mac_params	 params;
-	struct fixed_phy_status *fixed_link;
+	struct fixed_phy_status *fixed_link = NULL;
 
 	mac_dev->set_promisc		= memac_set_promiscuous;
 	mac_dev->change_addr		= memac_modify_mac_address;