LU-4423 ptlrpc: use 64-bit time for debugfs import state output

LU-4423 ptlrpc: use 64-bit time for debugfs import state output

This time is only printed in debugfs, and can be easily converted
to 64-bit to avoid overflowing on 32-bit systems in 2038.

Linux-commit: 74e489aa9cce1ec8f8a44ecc1651cf06b61db204

Change-Id: I7ee171367e90ef32b29bce31abddd4e17eb8daf2
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/25409
Tested-by: Jenkins
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>