LU-9019 o2iblnd: use 64-bit ibn_incarnation computation

LU-9019 o2iblnd: use 64-bit ibn_incarnation computation

ibn_incarnation is a 64-bit value, but using timeval to compute
it will cause an overflow in 2038. This changes it to use
ktime_get_real_ns() instead.

Change-Id: I4698a046ece30a85c93ac1f12e541d81fcfd70f2
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/23267
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>