usb/gadget: f_midi: convert tasklets to use new tasklet_setup() API

In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.
Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200817090209.26351-5-allen.cryptic@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/f_midi.c

@@ -698,9 +698,9 @@ static void f_midi_transmit(struct f_midi *midi)
 	f_midi_drop_out_substreams(midi);
 }
 
-static void f_midi_in_tasklet(unsigned long data)
+static void f_midi_in_tasklet(struct tasklet_struct *t)
 {
-	struct f_midi *midi = (struct f_midi *) data;
+	struct f_midi *midi = from_tasklet(midi, t, tasklet);
 	f_midi_transmit(midi);
 }
 
@@ -875,7 +875,7 @@ static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 	int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0;
 
 	midi->gadget = cdev->gadget;
-	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
+	tasklet_setup(&midi->tasklet, f_midi_in_tasklet);
 	status = f_midi_register_card(midi);
 	if (status < 0)
 		goto fail_register;