lightnvm: 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: Matias Bjorling <mb@lightnvm.io>
Cc: linux-block@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

drivers/lightnvm/pblk-core.c

@@ -270,9 +270,9 @@ static void pblk_write_kick(struct pblk *pblk)
 	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(1000));
 }
 
-void pblk_write_timer_fn(unsigned long data)
+void pblk_write_timer_fn(struct timer_list *t)
 {
-	struct pblk *pblk = (struct pblk *)data;
+	struct pblk *pblk = from_timer(pblk, t, wtimer);
 
 	/* kick the write thread every tick to flush outstanding data */
 	pblk_write_kick(pblk);