Consolidate curFrame fields in thread storage

We ended up with two locations in the Thread structure for saved
Dalvik frame pointer.  This change consolidates them.

Change-Id: I78f288e4e57e232f29663be930101e775bfe370f
diff --git a/vm/mterp/portable/stubdefs.cpp b/vm/mterp/portable/stubdefs.cpp
index de9a8e7..57ff35c 100644
--- a/vm/mterp/portable/stubdefs.cpp
+++ b/vm/mterp/portable/stubdefs.cpp
@@ -21,7 +21,8 @@
  */
 #define PC_FP_TO_SELF()                                                    \
     self->interpSave.pc = pc;                                              \
-    self->interpSave.fp = fp;
+    self->interpSave.curFrame = fp;
+#define PC_TO_SELF() self->interpSave.pc = pc;
 
 /*
  * Instruction framing.  For a switch-oriented implementation this is