fellow_cache: Factor out seglist loading wait

src/fellow_cache.c

@@ -2297,6 +2297,16 @@ fellow_cache_seglists_need(const struct fellow_cache *fc,
 	AZ(fc->taskrun(fellow_cache_seglists_load, fclsp, &fclsp->state));
 }
 
+static void
+fellow_cache_seglists_wait_locked(struct fellow_cache_obj *fco)
+{
+
+	CHECK_OBJ_NOTNULL(fco, FELLOW_CACHE_OBJ_MAGIC);
+	while (fco->seglstate == SEGL_LOADING)
+		AZ(pthread_cond_wait(&fco->cond, &fco->mtx));
+	assert(fco->seglstate == SEGL_DONE || fco->seglstate == SEGL_NEED);
+}
+
 /*
  * MEM LAYOUT
  *
@@ -3734,9 +3744,7 @@ fellow_cache_obj_slim(const struct fellow_cache *fc,
 	AZ(pthread_mutex_lock(&fco->mtx));
 
 	// we wait for loading complete to be able to ignore pending
-	while (fco->seglstate == SEGL_LOADING)
-		AZ(pthread_cond_wait(&fco->cond, &fco->mtx));
-	assert(fco->seglstate == SEGL_DONE || fco->seglstate == SEGL_NEED);
+	fellow_cache_seglists_wait_locked(fco);
 
 	/* anything to do at all? */
 	while ((fcs = fcsc_next_ignore_pending(&c)) != NULL)