Remove unused variable.

stepper.py

@@ -26,7 +26,6 @@ def step(insns, terminator, blocks, stack_frames, ssa_env, global_env, memory,
     res = None
     if isinstance(next_insn, ll.Binop):
         bop = next_insn.bop
-        ty = next_insn.ty
         left = next_insn.left
         right = next_insn.right
         left_v = eval_oper(left, ssa_env, global_env)
@@ -168,6 +167,7 @@ def eval_icmp(cnd, left, right):
             .format(cnd))
         return 0
 
+
 def gogo():
     p = parser.LLVMParser()
     p.build()