openrisc: Remove obsolete show_trace_task function

The function show_trace_task() was removed during linux 2.5 development
and replaced with show_stack().  This was never impemented for openrisc
but must have got in via copying from another architecture.  Just remove
it.
Signed-off-by: Stafford Horne <shorne@gmail.com>

arch/openrisc/kernel/traps.c

@@ -55,13 +55,6 @@ void show_stack(struct task_struct *task, unsigned long *esp)
 	unwind_stack(NULL, esp, print_trace);
 }
 
-void show_trace_task(struct task_struct *tsk)
-{
-	/*
-	 * TODO: SysRq-T trace dump...
-	 */
-}
-
 void show_registers(struct pt_regs *regs)
 {
 	int i;