Fix mingw build for multicast.c

https://github.com/Hamlib/Hamlib/issues/695

src/multicast.c

@@ -327,10 +327,7 @@ void *multicast_thread(void *vrig)
 #ifdef WIN32
 static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
 {
-    void GetWinsockErrorString(char *errorBuffer, DWORD errorBufferSize)
-    {
     int errorCode = WSAGetLastError();
-        DWORD charsWritten;
 
     FormatMessage(
         FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
@@ -341,11 +338,12 @@ static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
         errorBufferSize,
         NULL
     );
-    }
+    return errorBuffer;
+}
 #endif
 
-    int multicast_init(RIG * rig, char *addr, int port)
+int multicast_init(RIG *rig, char *addr, int port)
-    {
+{
 #ifdef _WIN32
     WSADATA wsaData;
 
@@ -445,10 +443,10 @@ static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
     //printf("threadid=%ld\n", rig->state.multicast->threadid);
     rig->state.multicast->multicast_running = 1;
     return RIG_OK;
-    }
+}
 
-    void multicast_close(RIG * rig)
+void multicast_close(RIG *rig)
-    {
+{
     int retval;
 
     // Leave the multicast group
@@ -465,11 +463,11 @@ static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
     {
         rig_debug(RIG_DEBUG_ERR, "%s: close: %s\n", __func__, strerror(errno));
     }
-    }
+}
 
 // if msglen=0 msg is assumed to be a string
-    int multicast_send(RIG * rig, const char *msg, int msglen)
+int multicast_send(RIG *rig, const char *msg, int msglen)
-    {
+{
     // Construct the message to send
     if (msglen == 0) { msglen = strlen((char *)msg); }
 
@@ -483,19 +481,14 @@ static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
         rig_debug(RIG_DEBUG_ERR, "%s: sendto: %s\n", __func__, strerror(errno));
         return -RIG_EIO;
     }
-        else
-        {
-//        printf("Sent %zd bytes to multicast group %s:%d\n", num_bytes, MULTICAST_ADDR,
-//               PORT);
-        }
 
     return num_bytes;
-    }
+}
 
 //#define TEST
 #ifdef TEST
-    int main(int argc, char *argv[])
+int main(int argc, char *argv[])
-    {
+{
     RIG *rig;
     rig_model_t myrig_model;
     rig_set_debug_level(RIG_DEBUG_NONE);
@@ -520,5 +513,5 @@ static char *GetWinsockLastError(char *errorBuffer, DWORD errorBufferSize)
     pthread_join(rig->state.multicast->threadid, NULL);
     pthread_exit(NULL);
     return 0;
-    }
+}
 #endif