scsi: bfa: Make restart_bfa static

Fix sparse warning:

drivers/scsi/bfa/bfad.c:1491:1: warning:
 symbol 'restart_bfa' was not declared. Should it be static?

Link: https://lore.kernel.org/r/20190930094327.46836-1-yuehaibing@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>