tracing: Shutdown tracing in drain
tracing: Shutdown tracing in drain

First of all, shutdown that happens after nodetoo drain leaves
tracing up-n-running, so it's effectively a bugfix. But also
a step towards unified drain and drain_on_shutdown.

Keeping this bit in drain seems to be required because drain
stops transport, flushes column families and shuts commitlog
down. Any tracing activity happening after it looks uncalled
for.

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla