ixgbe: fix VFIO interrupt vector

The vector number may change during 'dev_start'. Before enabling a new vector mapping,
it's necessary to disable/unmap the previous setting.

Fixes: 7ab8500037 ("ixgbe: fix VF start with PF stopped")

Reported-by: Yong Liu <yong.liu@intel.com>
Signed-off-by: Cunming Liang <cunming.liang@intel.com>
Tested-by: Yong Liu <yong.liu@intel.com>
Acked-by: Wenzhuo Lu <wenzhuo.lu@intel.com>

drivers/net/ixgbe/ixgbe_ethdev.c

@@ -1991,6 +1991,9 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 		return -EINVAL;
 	}
 
+	/* disable uio/vfio intr/eventfd mapping */
+	rte_intr_disable(intr_handle);
+
 	/* stop adapter */
 	hw->adapter_stopped = 0;
 	ixgbe_stop_adapter(hw);