[SCSI] fcoe: use kthread_create_on_node

Since fcoe_percpu_thread_create() creates percpu kthread, it makes sense
to use kthread_create_on_node() to get proper NUMA affinity for kthread
stack.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>