LU-3069 build: fix 'integer handling' issues

Fix 'program hangs' defects found by Coverity version 6.5.1:
Improper use of negative value (NEGATIVE_RETURNS)
Variable is passed to a parameter that cannot be negative.
Macro compares unsigned to 0 (NO_EFFECT)
This comparison is always true.
Operands don't affect result (CONSTANT_EXPRESSION_RESULT)
Test is always false regardless of the values of its operands.
Wrong operator used (CONSTANT_EXPRESSION_RESULT)
Test is always true regardless of the values of its operand.

Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: I687a05aaffad13caaebe16edbc4f93ef7ca3413f
Reviewed-on: http://review.whamcloud.com/5888
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>