Address lock-order-inversion warning from TSAN.

Author: kishorenc

hnswlib/hnswalg.h

@@ -1099,14 +1099,15 @@ class HierarchicalNSW : public AlgorithmInterface<dist_t> {
             label_lookup_[label] = cur_c;
         }
 
+        std::unique_lock <std::mutex> templock(global);
+
         std::unique_lock <std::mutex> lock_el(link_list_locks_[cur_c]);
         int curlevel = getRandomLevel(mult_);
         if (level > 0)
             curlevel = level;
 
         element_levels_[cur_c] = curlevel;
 
-        std::unique_lock <std::mutex> templock(global);
         int maxlevelcopy = maxlevel_;
         if (curlevel <= maxlevelcopy)
             templock.unlock();