du: recurse: fix path

path is not fixed up on exit from recursive step, this leads to
incorrect paths in du's output.

% find D
D
D/E
D/E/F
D/E/F/a2
D/E/F/b2
D/E/a1
D/E/b1
D/a
D/b

% du D
4       D/E/F
8       D/E
12      D

% ~/sbase/du D
4       D/E/F/b2
8       D/E/b1
12      D

libutil/recurse.c

@@ -90,6 +90,8 @@ recurse(int dirfd, const char *name, void *data, struct recursor *r)
 				r->depth--;
 			}
 		}
+		r->path[pathlen - 1] = '\0';
+		r->pathlen = pathlen - 1;
 		closedir(dp);
 	}