Merge pull request #28085 from rzarzynski/wip-crimson-no-atomics-in-refcntobj

crimson, common: RefCountedObj doesn't use atomics in Seastar builds.

Reviewed-by: Kefu Chai <kchai@redhat.com>

src/common/RefCountedObj.h

@@ -72,7 +72,12 @@ public:
   }
 
 private:
+#ifndef WITH_SEASTAR
   mutable std::atomic<uint64_t> nref;
+#else
+  // crimson is single threaded at the moment
+  mutable uint64_t nref;
+#endif
   CephContext *cct;
 };