BRT: Don't call brt_pending_remove() on holes/embedded

We are doing exactly the same checks around all brt_pending_add().

Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.

module/zfs/dbuf.c

@@ -2578,8 +2578,11 @@ dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
 		 * We are freeing a block that we cloned in the same
 		 * transaction group.
 		 */
-		brt_pending_remove(dmu_objset_spa(db->db_objset),
-		    &dr->dt.dl.dr_overridden_by, tx);
+		blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
+		if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
+			brt_pending_remove(dmu_objset_spa(db->db_objset),
+			    bp, tx);
+		}
 	}
 
 	dnode_t *dn = dr->dr_dnode;