fcoe: Reduce fcoe_sysfs_fcf_add() stack usage

This patch fixes the following compiler warning:

drivers/scsi/fcoe/fcoe_ctlr.c: In function fcoe_sysfs_fcf_add:
drivers/scsi/fcoe/fcoe_ctlr.c:211:1: warning: the frame size of 1480 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>