Back porting coverity issues fix patch from master branch.
Fix coverity issue:1111377 Unchecked return value
Fix coverity issue:1111381 Logically dead code
Fix coverity issue:1222992 Unchecked return value
Fix coverity issue:1222993 Unchecked return value
Remove meaningless minus check because of unsigned int variable.

Coverity issue #1111419, #1111420, #1111422.