media: drivers: improve a size determination

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

This issue was detected by using the Coccinelle software.

[mchehab@s-opensoure.com: merge similar patches into one]

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>

drivers/media/dvb-frontends/sp2.c

@@ -381,7 +381,7 @@ static int sp2_probe(struct i2c_client *client,
 
 	dev_dbg(&client->dev, "\n");
 
-	s = kzalloc(sizeof(struct sp2), GFP_KERNEL);
+	s = kzalloc(sizeof(*s), GFP_KERNEL);
 	if (!s) {
 		ret = -ENOMEM;
 		goto err;