Remove wrong use of errno in AsyncUDPSocket

Summary: [Folly] Remove wrong use of `errno` in `AsyncUDPSocket`.

Reviewed By: markisaa

Differential Revision: D23153435

fbshipit-source-id: f567aa97ebe243ff5b6ad99e300212df290800bb

folly/io/async/AsyncUDPSocket.cpp

@@ -117,7 +117,7 @@ void AsyncUDPSocket::init(sa_family_t family) {
     }
 #else /* SO_BUSY_POLL is not supported*/
     throw AsyncSocketException(
-        AsyncSocketException::NOT_OPEN, "SO_BUSY_POLL is not supported", errno);
+        AsyncSocketException::NOT_OPEN, "SO_BUSY_POLL is not supported");
 #endif
   }