Directory: eliminate attribute "have_stat"

src/db/plugins/simple/Directory.cxx

@@ -39,7 +39,8 @@
 
 Directory::Directory(std::string &&_path_utf8, Directory *_parent)
 	:parent(_parent),
-	 mtime(0), have_stat(false),
+	 mtime(0),
+	 inode(0), device(0),
 	 path(std::move(_path_utf8)),
 	 mounted_database(nullptr)
 {

src/db/plugins/simple/Directory.hxx

@@ -95,7 +95,6 @@ struct Directory {
 	Directory *parent;
 	time_t mtime;
 	unsigned inode, device;
-	bool have_stat; /* not needed if ino_t == dev_t == 0 is impossible */
 
 	std::string path;
 

src/db/update/Walk.cxx

@@ -71,7 +71,6 @@ directory_set_stat(Directory &dir, const FileInfo &info)
 {
 	dir.inode = info.inode;
 	dir.device = info.device;
-	dir.have_stat = true;
 }
 
 inline void
@@ -167,7 +166,7 @@ FindAncestorLoop(Storage &storage, Directory *parent,
 		return 0;
 
 	while (parent) {
-		if (!parent->have_stat &&
+		if (parent->device == 0 && parent->inode == 0 &&
 		    !update_directory_stat(storage, *parent))
 			return -1;