4045 zfs write throttle & i/o scheduler performance work
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>

@@ -430,11 +430,11 @@
                         }
 
                         zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
                             mc->mc_vd, mc->mc_offset,
                             zio->io_data, zio->io_size,
-                            ZIO_TYPE_WRITE, zio->io_priority,
+                            ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE,
                             ZIO_FLAG_IO_REPAIR | (unexpected_errors ?
                             ZIO_FLAG_SELF_HEAL : 0), NULL, NULL));
                 }
         }
 }