tile: remove an unused variable in copy_thread()

Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

arch/tile/kernel/process.c

@@ -159,7 +159,7 @@ static void save_arch_state(struct thread_struct *t);
 int copy_thread(unsigned long clone_flags, unsigned long sp,
 		unsigned long arg, struct task_struct *p)
 {
-	struct pt_regs *childregs = task_pt_regs(p), *regs = current_pt_regs();
+	struct pt_regs *childregs = task_pt_regs(p);
 	unsigned long ksp;
 	unsigned long *callee_regs;