i40e: Make struct i40e_stats const

Move some data to text

$ size drivers/net/ethernet/intel/i40e/i40e_ethtool.o*
   text	   data	    bss	    dec	    hex	filename
  25012	      0	     32	  25044	   61d4	drivers/net/ethernet/intel/i40e/i40e_ethtool.o.new
  22868	   2120	     32	  25020	   61bc	drivers/net/ethernet/intel/i40e/i40e_ethtool.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -104,7 +104,7 @@ static const struct i40e_stats i40e_gstrings_misc_stats[] = {
  * The PF_STATs are appended to the netdev stats only when ethtool -S
  * is queried on the base PF netdev, not on the VMDq or FCoE netdev.
  */
-static struct i40e_stats i40e_gstrings_stats[] = {
+static const struct i40e_stats i40e_gstrings_stats[] = {
 	I40E_PF_STAT("rx_bytes", stats.eth.rx_bytes),
 	I40E_PF_STAT("tx_bytes", stats.eth.tx_bytes),
 	I40E_PF_STAT("rx_unicast", stats.eth.rx_unicast),