LU-11049 ssk: correctly handle null byte by lgss_sk

LU-11049 ssk: correctly handle null byte by lgss_sk

lgss_sk must include null byte with fsname and nodemap info taken from
command line.

Lustre-change: https://review.whamcloud.com/32510
Lustre-commit: 10173500fdb7332c369e72dc00e365f329d20f20

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I7bd41ba3fc9fc56e4049f8080c0ee95ba26334a9
Reviewed-on: https://review.whamcloud.com/33358
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jeremy Filizetti <jeremy.filizetti@gmail.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>