Remove unused jit_debug unique_ptr.

Change-Id: I39ed4fdd5695fefff235b6c40d83d9780fc5b75b
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 57207de..0dd95cf 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -144,7 +144,6 @@
 
   bool return_address_attempt = false;
   bool adjust_pc = false;
-  std::unique_ptr<JitDebug> jit_debug;
   for (; frames_.size() < max_frames_;) {
     uint64_t cur_pc = regs_->pc();
     uint64_t cur_sp = regs_->sp();