Add VZONEROOT flag because not all zone roots have VROOT set.

*** 413,422 ****
--- 413,429 ----
   * expectations about normal VFS behavior.
   */
  #define VTRAVERSE       0x80000
  
  /*
+  * Indicates the vnode is a zone's root ("/" in-zone). A zone's root does NOT
+  * have to be a filesystem root, even if many zone brands guaranteed that.
+  */
+ #define VZONEROOT       0x100000
+ 
+ 
+ /*
   * Vnode attributes.  A bit-mask is supplied as part of the
   * structure to indicate the attributes the caller wants to
   * set (setattr) or extract (getattr).
   */