LU-4629 libcfs: fix buffer overflow of string buffer

LU-4629 libcfs: fix buffer overflow of string buffer

Buffer overflow of string buffer due to non null terminated string.
Use strlcpy() when it's justifiable.
Use sizeof(var) instead of constants.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: Ib8d5493898a292e3c764170d0a0870bee26b23a0
Reviewed-on: http://review.whamcloud.com/9389
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>