in 372a4d1b79, we introduced a change
which was for debugging the logging message. but the logging message
intended for printing the temp_dir not prints an `optional<int>`. this
is both confusing, and more importantly, it hurts the debuggability.
in this change, the related change is reverted.
Fixesscylladb/scylladb#20408
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
(cherry picked from commit d26bb9ae30)
Closesscylladb/scylladb#20434