ixgbe: fix for unused variable warning with certain config

If CONFIG_PCI_IOV isn't defined we get an "unused variable" warining so
now wrap the variable declaration like it's usage already was.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c

@@ -291,7 +291,9 @@ static int ixgbe_pci_sriov_disable(struct pci_dev *dev)
 {
 	struct ixgbe_adapter *adapter = pci_get_drvdata(dev);
 	int err;
+#ifdef CONFIG_PCI_IOV
 	u32 current_flags = adapter->flags;
+#endif
 
 	err = ixgbe_disable_sriov(adapter);