[COMMIT seastar master] reactor: drop stale comment

[Commit Bot]

From: Kefu Chai <tcha...@gmail.com>
Committer: Pavel Emelyanov <xe...@scylladb.com>
Branch: master

reactor: drop stale comment

the per-shard `_lowres_clock_impl` member variable was dropped in
5809978cf345b7ac4a7c584e2ab6478bae03b448. the comment added in
f057084a647b6d088f7a352eca62fe4cce68b733 does not apply anymore.
so let's just drop it.

Signed-off-by: Kefu Chai <tcha...@gmail.com>

Closes #1228

---
diff --git a/src/core/reactor.cc b/src/core/reactor.cc
--- a/src/core/reactor.cc
+++ b/src/core/reactor.cc
@@ -4175,7 +4175,6 @@ void smp::configure(const smp_options& smp_opts, const reactor_options& reactor_
inited->wait();

engine().configure(reactor_opts);
- // The raw `new` is necessary because of the private constructor of `lowres_clock_impl`.
}

bool smp::poll_queues() {