directory: convert "stat" to a bool

src/directory.h

@@ -43,7 +43,7 @@ struct directory {
 	time_t mtime;
 	ino_t inode;
 	dev_t device;
-	unsigned stat; /* not needed if ino_t == dev_t == 0 is impossible */
+	bool stat; /* not needed if ino_t == dev_t == 0 is impossible */
 	char path[sizeof(long)];
 };
 

src/update_walk.c

@@ -86,7 +86,7 @@ directory_set_stat(struct directory *dir, const struct stat *st)
 {
 	dir->inode = st->st_ino;
 	dir->device = st->st_dev;
-	dir->stat = 1;
+	dir->stat = true;
 }
 
 static void