LU-3427 build: fix 'error handling' issues

LU-3427 build: fix 'error handling' issues

Fix 'error handling' issues found by Coverity version 6.5.1:
Unchecked return value (CHECKED_RETURN)
Calling function without checking return value.

Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Change-Id: I67d667b405f292604290a49e69c963500d98278e
Reviewed-on: http://review.whamcloud.com/7103
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Bobbie Lind <bobbie.j.lind@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>