scsi: fnic: use 64-bit timestamps

struct timespec is deprecated since it overflows in 2038 on 32-bit
architectures, so we should use timespec64 consistently.

I'm slightly adapting the format strings here, to make sure we print the
nanoseconds with the correct number of leading zeroes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>