ixgbe: Use VMDq offset to indicate the default pool

This change makes it so that we can use the VMDq ring feature offset value
to determine the default pool instead of using num_vfs.  The reason for
this change is to avoid issues should we fail to allocate vfinfo but have
pre-existing VFs.  What should happen in this case is that num_vfs will go
to 0, but the VMDq offset will contain the location of the first PF pool.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Sibai Li <Sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index f7f6fe2..c236500 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -113,7 +113,7 @@
 #define IXGBE_MAX_VFTA_ENTRIES          128
 #define MAX_EMULATION_MAC_ADDRS         16
 #define IXGBE_MAX_PF_MACVLANS           15
-#define VMDQ_P(p)   ((p) + adapter->num_vfs)
+#define VMDQ_P(p)   ((p) + adapter->ring_feature[RING_F_VMDQ].offset)
 #define IXGBE_82599_VF_DEVICE_ID        0x10ED
 #define IXGBE_X540_VF_DEVICE_ID         0x1515