net/ixgbevf: make array api static const, makes object smaller

Don't populate the array API on the stack but instead make it
static const. Makes the object code smaller by 58 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  82969	   9763	    256	  92988	  16b3c	ixgbevf/ixgbevf_main.o

After:
   text	   data	    bss	    dec	    hex	filename
  82815	   9859	    256	  92930	  16b02	ixgbevf/ixgbevf_main.o

(gcc version 9.2.1, amd64)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

@@ -2261,12 +2261,14 @@ static void ixgbevf_init_last_counter_stats(struct ixgbevf_adapter *adapter)
 static void ixgbevf_negotiate_api(struct ixgbevf_adapter *adapter)
 {
 	struct ixgbe_hw *hw = &adapter->hw;
-	int api[] = { ixgbe_mbox_api_14,
+	static const int api[] = {
+		ixgbe_mbox_api_14,
 		ixgbe_mbox_api_13,
 		ixgbe_mbox_api_12,
 		ixgbe_mbox_api_11,
 		ixgbe_mbox_api_10,
-		      ixgbe_mbox_api_unknown };
+		ixgbe_mbox_api_unknown
+	};
 	int err, idx = 0;
 
 	spin_lock_bh(&adapter->mbx_lock);