[LibOS] Fix the storage leaks pointed by new_map in case of malloc fails to fd_new
get_new_handle_map will return a pointer for new_map, which could be NULL after examing the implementation of get_new_handle_map function.
In this case, accessing new_map->fd_top will cause undefined behavior. We need to add a check for new_map before accessing its member.
if the code error out and function return the error, allocated new_map is not freed, causing potential information leakage
Signed-off-by: Gary <gang1.wang@intel.com>