3006 VERIFY[S,U,P] and ASSERT[S,U,P] frequently check if first argument is zero

*** 706,716 ****
          ASSERT(dmu_tx_is_syncing(tx));
  
          obj = dsl_dataset_create_sync(dd, oa->lastname,
              oa->clone_origin, oa->flags, oa->cr, tx);
  
!         VERIFY3U(0, ==, dsl_dataset_hold_obj(dd->dd_pool, obj, FTAG, &ds));
          bp = dsl_dataset_get_blkptr(ds);
          if (BP_IS_HOLE(bp)) {
                  objset_t *os =
                      dmu_objset_create_impl(spa, ds, bp, oa->type, tx);
  
--- 706,716 ----
          ASSERT(dmu_tx_is_syncing(tx));
  
          obj = dsl_dataset_create_sync(dd, oa->lastname,
              oa->clone_origin, oa->flags, oa->cr, tx);
  
!         VERIFY0(dsl_dataset_hold_obj(dd->dd_pool, obj, FTAG, &ds));
          bp = dsl_dataset_get_blkptr(ds);
          if (BP_IS_HOLE(bp)) {
                  objset_t *os =
                      dmu_objset_create_impl(spa, ds, bp, oa->type, tx);
  
*** 1171,1181 ****
           * Create the root block IO
           */
          SET_BOOKMARK(&zb, os->os_dsl_dataset ?
              os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
              ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
!         VERIFY3U(0, ==, arc_release_bp(os->os_phys_buf, &os->os_phys_buf,
              os->os_rootbp, os->os_spa, &zb));
  
          dmu_write_policy(os, NULL, 0, 0, &zp);
  
          zio = arc_write(pio, os->os_spa, tx->tx_txg,
--- 1171,1181 ----
           * Create the root block IO
           */
          SET_BOOKMARK(&zb, os->os_dsl_dataset ?
              os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
              ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
!         VERIFY0(arc_release_bp(os->os_phys_buf, &os->os_phys_buf,
              os->os_rootbp, os->os_spa, &zb));
  
          dmu_write_policy(os, NULL, 0, 0, &zp);
  
          zio = arc_write(pio, os->os_spa, tx->tx_txg,
*** 1267,1279 ****
  {
          if ((flags & DNODE_FLAG_USERUSED_ACCOUNTED)) {
                  int64_t delta = DNODE_SIZE + used;
                  if (subtract)
                          delta = -delta;
!                 VERIFY3U(0, ==, zap_increment_int(os, DMU_USERUSED_OBJECT,
                      user, delta, tx));
!                 VERIFY3U(0, ==, zap_increment_int(os, DMU_GROUPUSED_OBJECT,
                      group, delta, tx));
          }
  }
  
  void
--- 1267,1279 ----
  {
          if ((flags & DNODE_FLAG_USERUSED_ACCOUNTED)) {
                  int64_t delta = DNODE_SIZE + used;
                  if (subtract)
                          delta = -delta;
!                 VERIFY0(zap_increment_int(os, DMU_USERUSED_OBJECT,
                      user, delta, tx));
!                 VERIFY0(zap_increment_int(os, DMU_GROUPUSED_OBJECT,
                      group, delta, tx));
          }
  }
  
  void