streamts: Fix const-correctness issues in Send() and write_packet()

- Change Send() parameter from unsigned char* to const unsigned char*.
- Update write_packet() to accept const uint8_t*.
- Fix invalid conversion error with GCC 14.

Confirmed working by building generic neutrino with GCC 14.


Origin commit data
------------------
Branch: ni/coolstream
Commit: 19cb83d8db
Author: Thilo Graf <dbt@novatux.de>
Date: 2025-03-10 (Mon, 10 Mar 2025)



------------------
This commit was generated by Migit

src/driver/streamts.cpp

@@ -113,48 +113,35 @@ bool CStreamInstance::Stop()
 	running = false;
 	return (OpenThreads::Thread::join() == 0);
 }
+
 #if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(61, 1, 100)
 bool CStreamInstance::Send(ssize_t r, const unsigned char *_buf)
 #else
 bool CStreamInstance::Send(ssize_t r,  unsigned char * _buf)
 #endif
 {
-	// lock fds for thread-safety
+    // OpenThreads::ScopedLock<OpenThreads::Mutex> m_lock(mutex);
     stream_fds_t cfds;
     mutex.lock();
     cfds = fds;
     mutex.unlock();
-
     int flags = 0;
     if (cfds.size() > 1)
         flags = MSG_DONTWAIT;
-
-	// iterate through all client sockets
-	for (auto it = cfds.begin(); it != cfds.end(); ++it)
-	{
+    for (stream_fds_t::iterator it = cfds.begin(); it != cfds.end(); ++it) {
         int i = 10;
-
-		// use a const pointer here to avoid conversion errors
         const unsigned char *b = _buf ? _buf : buf;
         ssize_t count = r;
-
-		do
-		{
-			// 'send' takes a const void*, so no cast needed
+        do {
             int ret = send(*it, b, count, flags);
-			if (ret > 0)
-			{
-				b += ret;   // move pointer further
-				count -= ret;   // reduce remaining bytes
+            if (ret > 0) {
+                b += ret;
+                count -= ret;
             }
         } while ((count > 0) && (i-- > 0));
-
-		// if count didn't drop to zero, there was some error
         if (count)
-			printf("CStreamInstance::%s: send error, fd %d: (%zd from %zd)\n", __FUNCTION__, *it, r - count, r);
-
+            printf("send err, fd %d: (%zd from %zd)\n", *it, r-count, r);
     }
-
     return true;
 }