ixgbe: define IXGBE_MAX_VFS_DRV_LIMIT macro and cleanup const 63

Because ixgbe driver limit the max number of VF
 functions could be enabled to 63, so define one macro IXGBE_MAX_VFS_DRV_LIMIT
 and cleanup the const 63 in code.

v3: revised for net-next tree.

Signed-off-by: Ethan Zhao <ethan.kernel@gmail.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index b445ad1..3fd4d3f 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -5067,7 +5067,7 @@
 
 	/* assign number of SR-IOV VFs */
 	if (hw->mac.type != ixgbe_mac_82598EB) {
-		if (max_vfs > 63) {
+		if (max_vfs > IXGBE_MAX_VFS_DRV_LIMIT) {
 			adapter->num_vfs = 0;
 			e_dev_warn("max_vfs parameter out of range. Not assigning any SR-IOV VFs\n");
 		} else {
@@ -8020,7 +8020,7 @@
 	ixgbe_init_mbx_params_pf(hw);
 	memcpy(&hw->mbx.ops, ii->mbx_ops, sizeof(hw->mbx.ops));
 	ixgbe_enable_sriov(adapter);
-	pci_sriov_set_totalvfs(pdev, 63);
+	pci_sriov_set_totalvfs(pdev, IXGBE_MAX_VFS_DRV_LIMIT);
 skip_sriov:
 
 #endif