i40e: Fix I40E_FLAG_VF_VLAN_PRUNING value

Commit c87c938f ("i40e: Add VF VLAN pruning") added new
PF flag I40E_FLAG_VF_VLAN_PRUNING but its value collides with
existing I40E_FLAG_TOTAL_PORT_SHUTDOWN_ENABLED flag.

Move the affected flag at the end of the flags and fix its value.

Reproducer:
[root@cnb-03 ~]# ethtool --set-priv-flags enp2s0f0np0 link-down-on-close on
[root@cnb-03 ~]# ethtool --set-priv-flags enp2s0f0np0 vf-vlan-pruning on
[root@cnb-03 ~]# ethtool --set-priv-flags enp2s0f0np0 link-down-on-close off
[ 6323.142585] i40e 0000:02:00.0: Setting link-down-on-close not supported on this port (because total-port-shutdown is enabled)
netlink error: Operation not supported
[root@cnb-03 ~]# ethtool --set-priv-flags enp2s0f0np0 vf-vlan-pruning off
[root@cnb-03 ~]# ethtool --set-priv-flags enp2s0f0np0 link-down-on-close off

The link-down-on-close flag cannot be modified after setting vf-vlan-pruning
because vf-vlan-pruning shares the same bit with total-port-shutdown flag
that prevents any modification of link-down-on-close flag.

Fixes: c87c938f ("i40e: Add VF VLAN pruning")
Cc: Mateusz Palczewski <mateusz.palczewski@intel.com>
Cc: Simon Horman <horms@kernel.org>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -580,7 +580,6 @@ struct i40e_pf {
 #define I40E_FLAG_DISABLE_FW_LLDP		BIT(24)
 #define I40E_FLAG_RS_FEC			BIT(25)
 #define I40E_FLAG_BASE_R_FEC			BIT(26)
-#define I40E_FLAG_VF_VLAN_PRUNING		BIT(27)
 /* TOTAL_PORT_SHUTDOWN
  * Allows to physically disable the link on the NIC's port.
  * If enabled, (after link down request from the OS)
@@ -603,6 +602,7 @@ struct i40e_pf {
  *   in abilities field of i40e_aq_set_phy_config structure
  */
 #define I40E_FLAG_TOTAL_PORT_SHUTDOWN_ENABLED	BIT(27)
+#define I40E_FLAG_VF_VLAN_PRUNING		BIT(28)
 
 	struct i40e_client_instance *cinst;
 	bool stat_offsets_loaded;