dirvote: Make dirvote_get_preferred_voting_intervals() static

This function doesn't need to be public from the dirvote common file (which
will get renamed in future commit) so move it to dirauth/dirvote.c and make it
static.

Part of #25988

Signed-off-by: David Goulet <dgoulet@torproject.org>

src/or/dirauth/dirvote.c

@@ -374,6 +374,22 @@ format_networkstatus_vote(crypto_pk_t *private_signing_key,
   return status;
 }
 
+/** Set *<b>timing_out</b> to the intervals at which we would like to vote.
+ * Note that these aren't the intervals we'll use to vote; they're the ones
+ * that we'll vote to use. */
+static void
+dirvote_get_preferred_voting_intervals(vote_timing_t *timing_out)
+{
+  const or_options_t *options = get_options();
+
+  tor_assert(timing_out);
+
+  timing_out->vote_interval = options->V3AuthVotingInterval;
+  timing_out->n_intervals_valid = options->V3AuthNIntervalsValid;
+  timing_out->vote_delay = options->V3AuthVoteDelay;
+  timing_out->dist_delay = options->V3AuthDistDelay;
+}
+
 /* =====
  * Consensus generation
  * ===== */

src/or/dirvote_common.c

@@ -19,22 +19,6 @@
  * Vote scheduling
  * ===== */
 
-/** Set *<b>timing_out</b> to the intervals at which we would like to vote.
- * Note that these aren't the intervals we'll use to vote; they're the ones
- * that we'll vote to use. */
-void
-dirvote_get_preferred_voting_intervals(vote_timing_t *timing_out)
-{
-  const or_options_t *options = get_options();
-
-  tor_assert(timing_out);
-
-  timing_out->vote_interval = options->V3AuthVotingInterval;
-  timing_out->n_intervals_valid = options->V3AuthNIntervalsValid;
-  timing_out->vote_delay = options->V3AuthVoteDelay;
-  timing_out->dist_delay = options->V3AuthDistDelay;
-}
-
 /** Return the start of the next interval of size <b>interval</b> (in
  * seconds) after <b>now</b>, plus <b>offset</b>. Midnight always
  * starts a fresh interval, and if the last interval of a day would be

src/or/dirvote_common.h

@@ -52,7 +52,6 @@ typedef struct {
 
 extern voting_schedule_t voting_schedule;
 
-void dirvote_get_preferred_voting_intervals(vote_timing_t *timing_out);
 time_t dirvote_get_start_of_next_interval(time_t now,
                                           int interval,
                                           int offset);