better offset handling

src/lib9pclient/fs.c

diff --git a/src/lib9pclient/fs.c b/src/lib9pclient/fs.c
index eda023b..e51876c 100644
--- a/src/lib9pclient/fs.c
+++ b/src/lib9pclient/fs.c
@@ -259,6 +259,11 @@
 	fs->freefid = f->next;
 	fs->ref++;
 	qunlock(&fs->lk);
+	f->offset = 0;
+	f->mode = -1;
+	f->qid.path = 0;
+	f->qid.vers = 0;
+	f->qid.type = 0;
 	return f;
 }