ixgbe: prevent link checks while resetting

ixgbe: prevent link checks while resetting

It some situations the driver sets __IXGBE_RESETTING and then
__IXGBE_DOWN flags. It is possible a link check may sneak in
between.

This patch adds check for both flags.
The idea is to reduce register reads while the PHY is resetting.

(cherry picked from commit 7edebf9a6aac07e2ebb3901b60672293a7139ad0)
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Joe Jin <joe.jin@oracle.com>