The link status got from link status register was not correct,
because register has been reset when ports reset.
After port reset, set the link status down.
Fixes: c431ec66c54c ("net/igb: support setting link up or down")
Cc: stable@dpdk.org
Signed-off-by: Lunyuan Cui <lunyuanx.cui@intel.com>
Acked-by: Wenzhuo Lu <wenzhuo.lu@intel.com>