media: media/saa7146: 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. This requires adding a pointer to
hold the timer's target file, as there won't be a way to pass this in the
future.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

include/media/drv-intf/saa7146_vv.h

@@ -107,6 +107,7 @@ struct saa7146_vv
 	struct saa7146_dmaqueue		vbi_dmaq;
 	struct v4l2_vbi_format		vbi_fmt;
 	struct timer_list		vbi_read_timeout;
+	struct file			*vbi_read_timeout_file;
 	/* vbi workaround interrupt queue */
 	wait_queue_head_t		vbi_wq;
 	int				vbi_fieldcount;