Suppress share error on mount

Until code is added to support automatically sharing datasets
we should return success instead of failure.  This prevents the
command line tools from returning a non-zero error code.  While
a user likely won't notice this, test scripts like zconfig.sh
do and correctly fail because of it.

lib/libzfs/libzfs_mount.c

@@ -797,8 +797,9 @@ zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
 		    dgettext(TEXT_DOMAIN, "cannot share '%s': %s"),
 		    zfs_get_name(zhp), _sa_errorstr != NULL ?
 		    _sa_errorstr(ret) : "");
-#endif /* HAVE_SHARE */
 		return (-1);
+#endif /* HAVE_SHARE */
+		return (0);
 	}
 
 	for (curr_proto = proto; *curr_proto != PROTO_END; curr_proto++) {