e100: Fix passing zero to 'PTR_ERR' warning in e100_load_ucode_wait

Fix a static code checker warning:
drivers/net/ethernet/intel/e100.c:1349
 e100_load_ucode_wait() warn: passing zero to 'PTR_ERR'
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e100.c

@@ -1345,8 +1345,8 @@ static inline int e100_load_ucode_wait(struct nic *nic)
 
 	fw = e100_request_firmware(nic);
 	/* If it's NULL, then no ucode is required */
-	if (!fw || IS_ERR(fw))
-		return PTR_ERR(fw);
+	if (IS_ERR_OR_NULL(fw))
+		return PTR_ERR_OR_ZERO(fw);
 
 	if ((err = e100_exec_cb(nic, (void *)fw, e100_setup_ucode)))
 		netif_err(nic, probe, nic->netdev,