VFS: Wrap with HAVE_SHARE

Certain NFS/SMB share functionality is not yet in place.  These
functions used to be wrapped with the generic HAVE_ZPL to prevent
them from being compiled.  I still don't want them compiled but
I'm working toward eliminating the use of HAVE_ZPL.  So I'm just
renaming the wrapper here to HAVE_SHARE.  They still won't be
compiled until all the share issues are worked through.  Share
support is the last missing piece from zfs_ioctl.c.

module/zfs/zfs_znode.c

@@ -285,6 +285,7 @@ zfs_create_op_tables()
 int
 zfs_create_share_dir(zfsvfs_t *zfsvfs, dmu_tx_t *tx)
 {
+#ifdef HAVE_SHARE
 	zfs_acl_ids_t acl_ids;
 	vattr_t vattr;
 	znode_t *sharezp;
@@ -326,6 +327,9 @@ zfs_create_share_dir(zfsvfs_t *zfsvfs, dmu_tx_t *tx)
 	kmem_cache_free(znode_cache, sharezp);
 
 	return (error);
+#else
+	return (0);
+#endif /* HAVE_SHARE */
 }
 
 /*