ixgbe: Remember to write ixfi changes after modifying

ixgbe: Remember to write ixfi changes after modifying

Orabug: 21669416

This patch corrects a bug in ixgbe_setup_ixfi_x550em where we were
reading and modifying IXGBE_KRM_LINK_CTRL_1 but forgot to write the
results back.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit bec4e68e6a45cc502901743fcfacaa9c076dc6d5)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>