LU-14437 gnilnd: use ktime_get_seconds() to get time

LU-14437 gnilnd: use ktime_get_seconds() to get time

Use ktime_get_seconds() to directly get the time inatead of
getting a timespec and converting it.

Fixes: 4b0e495e3c ("LU-14080 gnilnd: updates for SUSE 15 SP2")
Test-Parameters: trivial
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I256855ceb9e038a9960fa76fe6e3bfe63fb16580
Reviewed-on: https://review.whamcloud.com/41679
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>