Fix data race in fill of associator

Author: sbaldu

include/CLUEstering/DataFormats/alpaka/AssociationMap.hpp

@@ -71,7 +71,7 @@ namespace clue {
                                   uint32_t* sizes,
                                   size_t size) const {
       for (auto i : alpaka::uniformElements(acc, size)) {
-        auto prev = alpaka::atomicAdd(acc, &sizes[associations[i]], 1u);
+        alpaka::atomicAdd(acc, &sizes[associations[i]], 1u);
       }
     }
   };
@@ -86,8 +86,8 @@ namespace clue {
       for (auto i : alpaka::uniformElements(acc, size)) {
         const auto binId = bin_buffer[i];
         const auto position = temp_offsets[binId];
-        indexes[position] = i;
-        alpaka::atomicAdd(acc, &temp_offsets[binId], 1u);
+        auto prev = alpaka::atomicAdd(acc, &temp_offsets[binId], 1u);
+        indexes[prev] = i;
       }
     }
   };