async_hooks: avoid unneeded AsyncResource creation
Inspired by the callstack at https://github.com/nodejs/node/issues/34556#issuecomment-666743528
If the wanted store is equal to the active store it's not needed to create an AsyncResource.
Refs: https://github.com/nodejs/node/issues/34556#issuecomment-666743528
fyi @vdeturckheim @puzpuzpuz @Qard