Fix oatdump off-by-one

The dump of the pc <-> dex mapping tables was broken by the
recent mapping table restructuring change.  Fixed now.

Change-Id: I36c869e4a2853e18e021268b5b4eb49a4b76c970
diff --git a/src/oatdump.cc b/src/oatdump.cc
index c35d233..ab7f277 100644
--- a/src/oatdump.cc
+++ b/src/oatdump.cc
@@ -421,6 +421,7 @@
       return;
     }
 
+    ++raw_table;
     uint32_t length = *raw_table;
     ++raw_table;
     uint32_t pc_to_dex_entries = *raw_table;