Fix bound space bitmap assertion

Following the refactoring of space bitmap changing how binding of
bitmaps is implemented, the assertion was no longer valid:
  I4b1040d29f9ba99ea23c51f70a06af2ffbe496d4
It was checking that the two bitmap objects were located in the same
memory area which was never correct.
Change the assertion to instead check that the bitmaps' internal storage
address is the same.

Test: Initial stages of DaCapo/Xalan run with libartd.so runtime
Change-Id: I09761cdce65e74001363ef608d36b50202d62c9d
diff --git a/runtime/gc/collector/concurrent_copying.cc b/runtime/gc/collector/concurrent_copying.cc
index fb64ddd..48c595f 100644
--- a/runtime/gc/collector/concurrent_copying.cc
+++ b/runtime/gc/collector/concurrent_copying.cc
@@ -2680,7 +2680,8 @@
       // live bitmap. Deal with bound bitmaps.
       ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
       if (heap_->non_moving_space_->HasBoundBitmaps()) {
-        DCHECK_EQ(bitmap, heap_->non_moving_space_->GetLiveBitmap());
+        DCHECK_EQ(bitmap->Begin(),
+                  heap_->non_moving_space_->GetLiveBitmap()->Begin());
         bitmap = heap_->non_moving_space_->GetTempBitmap();
       } else {
         bitmap = heap_->non_moving_space_->GetLiveBitmap();