The CPU model name is printed multiple times when using -Xlog:os+cpu

The CPU model name will be printed multiple times if the platform only has model name but no flags (such as mips) when using -Xlog:os+cpu. "model_name_printed" should be initialized to "false" before the loop.

src/hotspot/os/linux/os_linux.cpp:

// Print the first "model name" line and the first "flags" line
// that we find and nothing more. We assume "model name" comes
// before "flags" so if we find a second "model name", then the
// "flags" field is considered missing.
static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) {
#if defined(IA32) || defined(AMD64)
  // Other platforms have less repetitive cpuinfo files
  FILE *fp = fopen("/proc/cpuinfo", "r");
  if (fp) {
    while (!feof(fp)) {
      if (fgets(buf, buflen, fp)) {
        // Assume model name comes before flags
        bool model_name_printed = false;
        if (strstr(buf, "model name") != NULL) {
          if (!model_name_printed) {
            st->print_raw("CPU Model and flags from /proc/cpuinfo:\n");
            st->print_raw(buf);
            model_name_printed = true;
          } else {
            // model name printed but not flags? Odd, just return
            fclose(fp);
            return true;
          }
        }
        // print the flags line too
        if (strstr(buf, "flags") != NULL) {
          st->print_raw(buf);
          fclose(fp);
          return true;
        }
      }
    }
    fclose(fp);
  }
#endif // x86 platforms