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

PR-URL: https://github.com/nodejs/node/pull/34616


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>
Reviewed-By: Andrey Pechkurov <apechkurov@gmail.com>