5045 use atomic_{inc,dec}_* instead of atomic_add_*

@@ -974,11 +974,11 @@
 vdev_uberblock_sync_done(zio_t *zio)
 {
         uint64_t *good_writes = zio->io_private;
 
         if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0)
-                atomic_add_64(good_writes, 1);
+                atomic_inc_64(good_writes);
 }
 
 /*
  * Write the uberblock to all labels of all leaves of the specified vdev.
  */

@@ -1049,11 +1049,11 @@
 vdev_label_sync_done(zio_t *zio)
 {
         uint64_t *good_writes = zio->io_private;
 
         if (zio->io_error == 0)
-                atomic_add_64(good_writes, 1);
+                atomic_inc_64(good_writes);
 }
 
 /*
  * If there weren't enough good writes, indicate failure to the parent.
  */