6319 assertion failed in zio_ddt_write: bp->blk_birth == txg
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

*** 1131,1140 ****
--- 1131,1142 ----
                  if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) {
                          BP_SET_DEDUP(bp, 1);
                          zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
                          return (ZIO_PIPELINE_CONTINUE);
                  }
+                 zio->io_bp_override = NULL;
+                 BP_ZERO(bp);
          }
  
          if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) {
                  /*
                   * We're rewriting an existing block, which means we're