Correct used bits from deflateUsed() for deflate_stored() case.

Author: madler

deflate.c

@@ -1754,8 +1754,10 @@ local block_state deflate_stored(deflate_state *s, int flush) {
         s->high_water = s->strstart;
 
     /* If the last block was written to next_out, then done. */
-    if (last)
+    if (last) {
+        s->bi_used = 8;
         return finish_done;
+    }
 
     /* If flushing and all input has been consumed, then done. */
     if (flush != Z_NO_FLUSH && flush != Z_FINISH &&