Removing bogus Py_DECREF() reported by Armin Rigo (SF bug 812353).

Even if a new dict is generated for locals, it is stored in
f->f_locals.
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 1c46f64..ffe9ec3 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -748,7 +748,6 @@
 	if (f->f_ncells || f->f_nfreevars) {
 		if (!(PyTuple_Check(f->f_code->co_cellvars)
 		      && PyTuple_Check(f->f_code->co_freevars))) {
-			Py_DECREF(locals);
 			return;
 		}
 		map_to_dict(f->f_code->co_cellvars,