staging: comedi: drivers: replace init_timer by setup_timer

This patch replaces init_timer and 2 step initialization of function and
data by setup_timer to make the code  more concise.

The issue was discovered using the following coccinelle script:

@@
expression ds, e1, e2;
@@

-init_timer (&ds);
+setup_timer (&ds, e1, e2);
...
-ds.function = e1;
...
-ds.data = e2;
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/comedi_test.c

@@ -420,9 +420,8 @@ static int waveform_attach(struct comedi_device *dev,
 	for (i = 0; i < s->n_chan; i++)
 		devpriv->ao_loopbacks[i] = s->maxdata / 2;
 
-	init_timer(&devpriv->timer);
-	devpriv->timer.function = waveform_ai_interrupt;
-	devpriv->timer.data = (unsigned long)dev;
+	setup_timer(&devpriv->timer, waveform_ai_interrupt,
+		    (unsigned long)dev);
 
 	dev_info(dev->class_dev,
 		 "%s: %i microvolt, %li microsecond waveform attached\n",