Kernel: Put too small unused network packets back into the list

Author: https://github.com/timschumi
Commit: df4ba7b430
Pull-request: https://github.com/SerenityOS/serenity/pull/14920
Reviewed-by: https://github.com/awesomekling

Kernel/Net/NetworkAdapter.cpp

@@ -122,7 +122,7 @@ RefPtr<PacketWithTimestamp> NetworkAdapter::acquire_packet_buffer(size_t size)
         if (unused_packet->buffer->capacity() >= size)
             return unused_packet;
 
-        // FIXME: Shouldn't we put existing buffers that are too small back into the list?
+        unused_packets.append(*unused_packet);
         return nullptr;
     });