qlcnic: Fix panic while setting VF's MAC address

o "qlcnic_sriov" structure pointer should be accessed only
  when SR-IOV is enabled. Access this pointer after SR-IOV
  PF check.
Signed-off-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NSucheta Chakraborty <sucheta.chakraborty@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c

@@ -1621,13 +1621,15 @@ int qlcnic_sriov_set_vf_mac(struct net_device *netdev, int vf, u8 *mac)
 {
 	struct qlcnic_adapter *adapter = netdev_priv(netdev);
 	struct qlcnic_sriov *sriov = adapter->ahw->sriov;
-	int i, num_vfs = sriov->num_vfs;
+	int i, num_vfs;
 	struct qlcnic_vf_info *vf_info;
 	u8 *curr_mac;
 
 	if (!qlcnic_sriov_pf_check(adapter))
 		return -EOPNOTSUPP;
 
+	num_vfs = sriov->num_vfs;
+
 	if (!is_valid_ether_addr(mac) || vf >= num_vfs)
 		return -EINVAL;