cstyle fixes
dsl_dataset_set_fsid_guid should use ZFS_SPACE_CHECK_RESERVED
dsl_dataset_set_fsid_guid _check and _sync func declared static,
removed from dsl_dataset.h
rewrite unique_valid
6333 ZFS should let the user specify or modify the fsid_guid of a dataset

*** 600,609 ****
--- 600,611 ----
                  clp->cl_allchildren = B_TRUE;
          } else if (prop == ZFS_PROP_CANMOUNT) {
                  clp->cl_prop = ZFS_PROP_MOUNTPOINT;
          } else if (prop == ZFS_PROP_VOLSIZE) {
                  clp->cl_prop = ZFS_PROP_MOUNTPOINT;
+         } else if (prop == ZFS_PROP_FSID_GUID) {
+                 clp->cl_prop = ZFS_PROP_MOUNTPOINT;
          } else {
                  clp->cl_prop = prop;
          }
          clp->cl_realprop = prop;