LU-9019 socklnd: use 64-bit incarnation time stamp

LU-9019 socklnd: use 64-bit incarnation time stamp

ksnn_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: I9a0b1f2c35d04d8dc2c8fd5e17e19583c8af5ff0
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/25690
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Olaf Weber <olaf@sgi.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>