Fix logging in socket.cpp (pytorch#137745)

Formatter shall avoid throwing exceptions as much as possible.

Fixes pytorch#128673 (comment)

Pull Request resolved: pytorch#137745
Approved by: https://github.com/d4l3k, https://github.com/Skylion007

torch/csrc/distributed/c10d/socket.cpp

@@ -220,11 +220,7 @@ std::string formatSockAddr(const struct ::sockaddr* addr, socklen_t len) {
         return fmt::format("[{}]:{}", ip, psai->sin6_port);
       }
     }
-
-    C10_THROW_ERROR(
-        DistNetworkError,
-        fmt::format(
-            "failed to format addr, unknown family={}", addr->sa_family));
+    return "?UNKNOWN?";
   }
   if (addr->sa_family == AF_INET) {
     return fmt::format("{}:{}", host, port);