Fix data race in ul_harq_entity.

srsue/hdr/stack/mac/ul_harq.h

@@ -100,9 +100,9 @@ private:
 
   srsran::ul_harq_cfg_t harq_cfg = {};
 
-  std::atomic<float> average_retx{0};
-  uint64_t           nof_pkts     = 0;
-  ra_proc*           ra_procedure = nullptr;
+  std::atomic<float>    average_retx{0};
+  std::atomic<uint64_t> nof_pkts{0};
+  ra_proc*              ra_procedure = nullptr;
 
   uint8_t cc_idx = 0;
 };