[media] s2255drv: cleanup vidioc_enum_fmt_cap()

"f" wasn't checked consistently, so static checkers complain.  This
function is always called with a valid "f" pointer, so I have removed
the check.

Also the indenting was messed up.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dean Anderson <linux-dev@sensoray.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/s2255drv.c

@@ -852,9 +852,7 @@ static int vidioc_querycap(struct file *file, void *priv,
 static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
 			       struct v4l2_fmtdesc *f)
 {
-	int index = 0;
-	if (f)
-		index = f->index;
+	int index = f->index;
 
 	if (index >= ARRAY_SIZE(formats))
 		return -EINVAL;