igb: add registers etc. printout code just before resetting adapters

This patch adds registers (,tx/rx rings' status and so on) printout
code just before resetting adapters. This will be helpful for detecting
the root cause of adapters reset.

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>