LU-9019 osd : remove struct timeval use in osd-ldiskfs

LU-9019 osd : remove struct timeval use in osd-ldiskfs

For brw_stats_show change the output to use a timespec64
type to avoid the overflow. Also change the format to
print the sub-second portion as 9 digits (nanoseconds)
for clarity, rather than printing six digits without
leading zeroes.

Both osd_write_prep() and osd_read_prep() want to report
the time it took to perform its operations in the
osd_get_page counter. This is currently done with
a call to do_gettimeofday with struct timeval which is
not 2038 safe. Move this operation to 64 bit time
handling.

Change-Id: I457ac799d855d2596220b6e0d0c5039e8b00021f
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/24896
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>