Do not redo the vnode tear-down work already done by insmntque() when

vnode cannot be put on the vnode list for mount.

Reported and tested by:	marck
Guilty party:	me
MFC after:	3 days

sys/fs/tmpfs/tmpfs_subr.c

@@ -391,11 +391,8 @@ loop:
 
 	vnode_pager_setsize(vp, node->tn_size);
 	error = insmntque(vp, mp);
-	if (error) {
-		vgone(vp);
-		vput(vp);
+	if (error)
 		vp = NULL;
-	}
 
 unlock:
 	TMPFS_NODE_LOCK(node);