Fix cpplint whitespace/blank_line issues

Change-Id: Ice937e95e23dd622c17054551d4ae4cebd0ef8a2
diff --git a/runtime/gc/accounting/space_bitmap.h b/runtime/gc/accounting/space_bitmap.h
index 5a1bfe3..bf4c1ed 100644
--- a/runtime/gc/accounting/space_bitmap.h
+++ b/runtime/gc/accounting/space_bitmap.h
@@ -174,6 +174,7 @@
     const size_t index = OffsetToIndex(offset);
     return &bitmap_begin_[index];
   }
+
  private:
   // TODO: heap_end_ is initialized so that the heap bitmap is empty, this doesn't require the -1,
   // however, we document that this is expected on heap_end_