ixgbe: Fix tx_restart_queue/non_eop_desc statistics counters

Fix the restart_queue and non_eop_desc counters from being
double-counted.  They are cumulative in each ring, so we don't want to
add them to the cumulative result in the adapter's master counter.
Otherwise, the stats will be inaccurate

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>