[sheepdog] Why creating config if the file is not found or empty?

[Ruoyu]

Hi Hitoshi,

As titled, once one of the two conditions is matched, sheep process 
create a new config file.
However, cluster info is not assigned at this time so that sheep will 
crash at one of the following step.
Why not directly reporting error message and return -1?


int init_config_file(void)
{
     int fd, ret;

     check_tmp_config();

     fd = open(config_path, O_RDONLY);
     if (fd < 0) {
         if (errno != ENOENT) {
             sd_err("failed to read config file, %m");
             return -1;
         }
         goto create;
     }

     ret = xread(fd, &config, sizeof(config));
     if (ret == 0) {
         close(fd);
         goto create;
     }
     if (ret < 0) {
         sd_err("failed to read config file, %m");
         goto out;
     }
...
}