Clean up mod union table

Fixed some formatting and removed unused forward declarations.

Bug: 19534862
Change-Id: Icfd5143e5bb7be0570248fd0f4bbf97125a9a35b
diff --git a/runtime/gc/accounting/mod_union_table-inl.h b/runtime/gc/accounting/mod_union_table-inl.h
index c756127..3a09634 100644
--- a/runtime/gc/accounting/mod_union_table-inl.h
+++ b/runtime/gc/accounting/mod_union_table-inl.h
@@ -28,7 +28,8 @@
 // A mod-union table to record image references to the Zygote and alloc space.
 class ModUnionTableToZygoteAllocspace : public ModUnionTableReferenceCache {
  public:
-  explicit ModUnionTableToZygoteAllocspace(const std::string& name, Heap* heap,
+  explicit ModUnionTableToZygoteAllocspace(const std::string& name,
+                                           Heap* heap,
                                            space::ContinuousSpace* space)
       : ModUnionTableReferenceCache(name, heap, space) {}