fm10k: update function header comment for fm10k_get_stats64

Re-word the comment to avoid stating that we return a value for this
void function. Additionally, there is no need to mention older kernels,
since this is the upstream kernel.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NKrishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k_netdev.c

@@ -1115,8 +1115,8 @@ void fm10k_reset_rx_state(struct fm10k_intfc *interface)
  * @netdev: network interface device structure
  * @stats: storage space for 64bit statistics
  *
- * Returns 64bit statistics, for use in the ndo_get_stats64 callback. This
- * function replaces fm10k_get_stats for kernels which support it.
+ * Obtain 64bit statistics in a way that is safe for both 32bit and 64bit
+ * architectures.
  */
 static void fm10k_get_stats64(struct net_device *netdev,
 			      struct rtnl_link_stats64 *stats)