simplify the stacktrace code

Simplify the stacktrace code:

 - remove the unused task argument to save_stack_trace, it's always
   current
 - remove the all_contexts flag, it's alwasy 0

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@suse.de>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/sh/kernel/stacktrace.c b/arch/sh/kernel/stacktrace.c
index 0d5268a..4bdd2f8 100644
--- a/arch/sh/kernel/stacktrace.c
+++ b/arch/sh/kernel/stacktrace.c
@@ -19,14 +19,7 @@
  */
 void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
 {
-	unsigned long *sp;
-
-	if (!task)
-		task = current;
-	if (task == current)
-		sp = (unsigned long *)current_stack_pointer;
-	else
-		sp = (unsigned long *)task->thread.sp;
+	unsigned long *sp = (unsigned long *)current_stack_pointer;
 
 	while (!kstack_end(sp)) {
 		unsigned long addr = *sp++;