LU-14080 gnilnd: updates for SUSE 15 SP2

LU-14080 gnilnd: updates for SUSE 15 SP2

gnilnd updates for SUSE 15 SP2

Use -Werror when checking for -Wno-stringop-truncation to
ensure the compile test is valid

Adjust for kernel dropping time_t, timeval, timespec
Adjust for kernel switching to timer_setup

Adjust for kernel dropping global_page_state(), use
nr_free_pages instead

Cleanup string format for stricter checking

Test-Parameters: trivial
HPE-bug-id: LUS-9453
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I5dcda1497fa5b1f2cf4a215517700f07374fcf7f
Reviewed-on: https://review.whamcloud.com/40426
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>