Fix tests based on coverity reports (#819)
* Partial #818, unused arg
* Partial #818, init var
* partail #818, fix va_args usage
* partail #818, handle f* calls and avoid possible call to malloc with negative values
* partail #818, prevent double free
* partail #818, resource leak if test fail
* partail #818, null deref fix
* partail #818, avoid double free on fp failure
* Partial #818, fix error msg
* Partial #818, leak on error
* Partial #818, null deref
* Partial #818, avoid possible negative index on failure
* partial #818, does not free if we return if requested new size overflow
* partial #818, avoid double free, free where the alloc happened