arm64: stacktrace: Constify stacktrace.h functions

on_accessible_stack() and on_task_stack() shouldn't (and don't)
modify their task argument, so it can be const.

This patch adds the appropriate modifiers. Whitespace violations in the
parameter lists are fixed at the same time.

No functional change.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dave Martin <dave.martin@arm.com>
[Mark: fixup const location, whitespace]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/stacktrace.h

@@ -64,7 +64,8 @@ static inline bool on_irq_stack(unsigned long sp,
 	return true;
 }
 
-static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
+static inline bool on_task_stack(const struct task_struct *tsk,
+				 unsigned long sp,
 				 struct stack_info *info)
 {
 	unsigned long low = (unsigned long)task_stack_page(tsk);
@@ -112,7 +113,7 @@ static inline bool on_overflow_stack(unsigned long sp,
  * We can only safely access per-cpu stacks from current in a non-preemptible
  * context.
  */
-static inline bool on_accessible_stack(struct task_struct *tsk,
+static inline bool on_accessible_stack(const struct task_struct *tsk,
 				       unsigned long sp,
 				       struct stack_info *info)
 {