The InterruptThrottleRate has been removed from ixgbe. Then Update
the comment.
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>