Handle large dnodes in dbuf_remap()

Illumos does not currently have the org.zfsonlinux:large_dnode pool
feature.

Signed-off-by: Tim Chase <tim@chase2k.com>

module/zfs/dbuf.c

@@ -3995,7 +3995,8 @@ dbuf_remap(dnode_t *dn, dmu_buf_impl_t *db, dmu_tx_t *tx)
 		dnode_phys_t *dnp = db->db.db_data;
 		ASSERT3U(db->db_dnode_handle->dnh_dnode->dn_type, ==,
 		    DMU_OT_DNODE);
-		for (int i = 0; i < db->db.db_size >> DNODE_SHIFT; i++) {
+		for (int i = 0; i < db->db.db_size >> DNODE_SHIFT;
+		    i += dnp[i].dn_extra_slots + 1) {
 			for (int j = 0; j < dnp[i].dn_nblkptr; j++) {
 				dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], tx);
 			}