submodule: refactor code to match current coding style

The submodule code has grown out-of-date regarding its coding style.
Update `git_submodule_reload` and `git_submodule_sync` to more closely
resemble what the rest of our code base uses.

src/submodule.c

@@ -1420,52 +1420,46 @@ cleanup:
 
 int git_submodule_sync(git_submodule *sm)
 {
-	int error = 0;
-	git_config *cfg = NULL;
-	git_buf key = GIT_BUF_INIT, effective_submodule_url = GIT_BUF_INIT;
+	git_buf key = GIT_BUF_INIT, url = GIT_BUF_INIT, remote_name = GIT_BUF_INIT;
 	git_repository *smrepo = NULL;
+	git_config *cfg = NULL;
+	int error = 0;
 
 	if (!sm->url) {
-		git_error_set(GIT_ERROR_SUBMODULE,
-			"no URL configured for submodule '%s'", sm->name);
+		git_error_set(GIT_ERROR_SUBMODULE, "no URL configured for submodule '%s'", sm->name);
 		return -1;
 	}
 
 	/* copy URL over to config only if it already exists */
+	if ((error = git_repository_config__weakptr(&cfg, sm->repo)) < 0 ||
+	    (error = git_buf_printf(&key, "submodule.%s.url", sm->name)) < 0 ||
+	    (error = git_submodule_resolve_url(&url, sm->repo, sm->url)) < 0 ||
+	    (error = git_config__update_entry(cfg, key.ptr, url.ptr, true, true)) < 0)
+		goto out;
 
-	if (!(error = git_repository_config__weakptr(&cfg, sm->repo)) &&
-		!(error = git_buf_printf(&key, "submodule.%s.url", sm->name)) &&
-		!(error = git_submodule_resolve_url(&effective_submodule_url, sm->repo, sm->url)))
-		error = git_config__update_entry(cfg, key.ptr, effective_submodule_url.ptr, true, true);
+	if (!(sm->flags & GIT_SUBMODULE_STATUS_IN_WD))
+		goto out;
 
 	/* if submodule exists in the working directory, update remote url */
+	if ((error = git_submodule_open(&smrepo, sm)) < 0 ||
+	    (error = git_repository_config__weakptr(&cfg, smrepo)) < 0)
+		goto out;
 
-	if (!error &&
-		(sm->flags & GIT_SUBMODULE_STATUS_IN_WD) != 0 &&
-		!(error = git_submodule_open(&smrepo, sm)))
-	{
-		git_buf remote_name = GIT_BUF_INIT;
-
-		if ((error = git_repository_config__weakptr(&cfg, smrepo)) < 0)
-			/* return error from reading submodule config */;
-		else if ((error = lookup_head_remote_key(&remote_name, smrepo)) < 0) {
-			git_error_clear();
-			error = git_buf_sets(&key, "remote.origin.url");
-		} else {
-			error = git_buf_join3(
-				&key, '.', "remote", remote_name.ptr, "url");
-			git_buf_dispose(&remote_name);
+	if (lookup_head_remote_key(&remote_name, smrepo) == 0) {
+		if ((error = git_buf_join3(&key, '.', "remote", remote_name.ptr, "url")) < 0)
+			goto out;
+	} else if ((error = git_buf_sets(&key, "remote.origin.url")) < 0) {
+		goto out;
 	}
 
-		if (!error)
-			error = git_config__update_entry(cfg, key.ptr, effective_submodule_url.ptr, true, false);
+	if ((error = git_config__update_entry(cfg, key.ptr, url.ptr, true, false)) < 0)
+		goto out;
 
+out:
 	git_repository_free(smrepo);
-	}
-
+	git_buf_dispose(&remote_name);
 	git_buf_dispose(&key);
-	git_buf_dispose(&effective_submodule_url);
-
+	git_buf_dispose(&url);
 	return error;
 }
 
@@ -1608,30 +1602,26 @@ static int submodule_update_head(git_submodule *submodule)
 
 int git_submodule_reload(git_submodule *sm, int force)
 {
-	int error = 0, isvalid;
-	git_config *mods;
+	git_config *mods = NULL;
+	int error;
 
 	GIT_UNUSED(force);
 
 	assert(sm);
 
-	isvalid = git_submodule_name_is_valid(sm->repo, sm->name, 0);
-	if (isvalid <= 0) {
+	if ((error = git_submodule_name_is_valid(sm->repo, sm->name, 0)) <= 0)
 		/* This should come with a warning, but we've no API for that */
-		return isvalid;
-	}
+		goto out;
+
+	if (git_repository_is_bare(sm->repo))
+		goto out;
 
-	if (!git_repository_is_bare(sm->repo)) {
 	/* refresh config data */
 	if ((error = gitmodules_snapshot(&mods, sm->repo)) < 0 && error != GIT_ENOTFOUND)
-			return error;
-		if (mods != NULL) {
-			error = submodule_read_config(sm, mods);
-			git_config_free(mods);
+		goto out;
 
-			if (error < 0)
-				return error;
-		}
+	if (mods != NULL && (error = submodule_read_config(sm, mods)) < 0)
+		goto out;
 
 	/* refresh wd data */
 	sm->flags &=
@@ -1639,12 +1629,13 @@ int git_submodule_reload(git_submodule *sm, int force)
 		  GIT_SUBMODULE_STATUS__WD_OID_VALID |
 		  GIT_SUBMODULE_STATUS__WD_FLAGS);
 
-		error = submodule_load_from_wd_lite(sm);
-	}
-
-	if (error == 0 && (error = submodule_update_index(sm)) == 0)
-		error = submodule_update_head(sm);
+	if ((error = submodule_load_from_wd_lite(sm)) < 0 ||
+	    (error = submodule_update_index(sm)) < 0 ||
+	    (error = submodule_update_head(sm)) < 0)
+		goto out;
 
+out:
+	git_config_free(mods);
 	return error;
 }