powerpc/watchdog: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NKees Cook <keescook@chromium.org>

arch/powerpc/kernel/watchdog.c

@@ -261,9 +261,8 @@ static void wd_timer_reset(unsigned int cpu, struct timer_list *t)
 	add_timer_on(t, cpu);
 }
 
-static void wd_timer_fn(unsigned long data)
+static void wd_timer_fn(struct timer_list *t)
 {
-	struct timer_list *t = this_cpu_ptr(&wd_timer);
 	int cpu = smp_processor_id();
 
 	watchdog_timer_interrupt(cpu);
@@ -287,7 +286,7 @@ static void start_watchdog_timer_on(unsigned int cpu)
 
 	per_cpu(wd_timer_tb, cpu) = get_tb();
 
-	setup_pinned_timer(t, wd_timer_fn, 0);
+	timer_setup(t, wd_timer_fn, TIMER_PINNED);
 	wd_timer_reset(cpu, t);
 }