arm64: Removed unused variable

arch/arm64/kernel/signal.c: In function ‘handle_signal’:
arch/arm64/kernel/signal.c:290:22: warning: unused variable ‘thread’ [-Wunused-variable]

Fixes: arm64: Remove signal translation and exec_domain
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/arm64/kernel/signal.c

@@ -287,7 +287,6 @@ static void setup_restart_syscall(struct pt_regs *regs)
  */
 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
-	struct thread_info *thread = current_thread_info();
 	struct task_struct *tsk = current;
 	sigset_t *oldset = sigmask_to_save();
 	int usig = ksig->sig;