Addresses #1577 Fix calculation of total memory size of a memarena

Use size of memarena struct instead of memarena pointer.
Include size of the 'other_bufs' array in size calculation.

git-svn-id: file:///svn/toku/tokudb@10500 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/memarena.c

@@ -140,7 +140,9 @@ void memarena_move_buffers(MEMARENA dest, MEMARENA source) {
 size_t
 memarena_total_memory_size (MEMARENA m)
 {
-    return m->size_of_other_bufs + m->buf_size + sizeof(m);
+    return (memarena_total_size_in_use(m) +
+            sizeof(*m) +
+            m->n_other_bufs * sizeof(*m->other_bufs));
 }
 
 size_t