Fix: Make FIFO access in rist_receiver_data_read2 thread-safe and improve error handling
- Added mutex protection around FIFO access in rist_receiver_data_read2 to prevent rare race conditions and FIFO desynchronization when reading from multiple threads.
- Replaced the assertion with error logging and a return code (-3) when FIFO desynchronization is detected, to avoid abrupt program termination and allow for graceful error handling.