commit-graph: Fix missing closedir in expire_commit_graphs

The function calls opendir() but missing the corresponding
closedir() before exit the function.
Add missing closedir() to fix it.

Signed-off-by: Miaoqian Lin <[email protected]>
Reviewed-by: Derrick Stolee <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: Yuuoniy

commit-graph.c

@@ -2269,6 +2269,8 @@ static void expire_commit_graphs(struct write_commit_graph_context *ctx)
 	}
 
 out:
+	if(dir)
+		closedir(dir);
 	strbuf_release(&path);
 }