ixgbe: fix ring assignment issues for SR-IOV and drop cases

This change fixes the fact that we would trigger a null pointer dereference
or specify the wrong ring if the rings were restored.  This change makes
certain that the DROP queue is a static value, and all other rings are
based on the ring offsets for the PF.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 596d794..074e9ba 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -2677,6 +2677,8 @@
 	/* program filters to filter memory */
 	err = ixgbe_fdir_write_perfect_filter_82599(hw,
 				&input->filter, input->sw_idx,
+				(input->action == IXGBE_FDIR_DROP_QUEUE) ?
+				IXGBE_FDIR_DROP_QUEUE :
 				adapter->rx_ring[input->action]->reg_idx);
 	if (err)
 		goto err_out_w_lock;