odb: adjust naming to free object sources

The functions `free_object_directory()` and `free_object_directories()`
are responsible for freeing a single object source or all object sources
connected to an object database, respectively. The associated structure
has been renamed from `struct object_directory` to `struct odb_source`
in a1e2581 (object-store: rename `object_directory` to `odb_source`,
2025-07-01) though, so the names are somewhat stale nowadays.

Rename them to mention the new struct name instead. Furthermore, while
at it, adapt them to our modern naming schema where we first have the
subject followed by a verb.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

odb.c

@@ -365,7 +365,7 @@ struct odb_source *odb_set_temporary_primary_source(struct object_database *odb,
 	return source->next;
 }
 
-static void free_object_directory(struct odb_source *source)
+static void odb_source_free(struct odb_source *source)
 {
 	free(source->path);
 	odb_clear_loose_cache(source);
@@ -387,7 +387,7 @@ void odb_restore_primary_source(struct object_database *odb,
 		BUG("we expect the old primary object store to be the first alternate");
 
 	odb->sources = restore_source;
-	free_object_directory(cur_source);
+	odb_source_free(cur_source);
 }
 
 char *compute_alternate_path(const char *path, struct strbuf *err)
@@ -1015,13 +1015,13 @@ struct object_database *odb_new(struct repository *repo)
 	return o;
 }
 
-static void free_object_directories(struct object_database *o)
+static void odb_free_sources(struct object_database *o)
 {
 	while (o->sources) {
 		struct odb_source *next;
 
 		next = o->sources->next;
-		free_object_directory(o->sources);
+		odb_source_free(o->sources);
 		o->sources = next;
 	}
 	kh_destroy_odb_path_map(o->source_by_path);
@@ -1039,7 +1039,7 @@ void odb_clear(struct object_database *o)
 	o->commit_graph = NULL;
 	o->commit_graph_attempted = 0;
 
-	free_object_directories(o);
+	odb_free_sources(o);
 	o->sources_tail = NULL;
 	o->loaded_alternates = 0;