LU-2074 build: fix 'copy into fixed size buffer' errors

LU-2074 build: fix 'copy into fixed size buffer' errors

Fix 'copy into fixed size buffer' defects found by Coverity
version 6.0.3:
Copy into fixed size buffer (STRING_OVERFLOW)
The fixed-size string might be overrun by copying without
checking the length.

Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Change-Id: Ia47e6ae132fe476fce202ce06d6fc655f9855012
Reviewed-on: http://review.whamcloud.com/4154
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>