staging: rts5208: rtsx.c: Alloc sizeof struct

Satisfy checkpatch message:  Prefer kzalloc(sizeof(*dev->chip)...) over
kzalloc(sizeof(struct rtsx_chip)...)
Signed-off-by: Wayne Porter <wporter82@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rts5208/rtsx.c

@@ -883,7 +883,7 @@ static int rtsx_probe(struct pci_dev *pci,
 	dev = host_to_rtsx(host);
 	memset(dev, 0, sizeof(struct rtsx_dev));
 
-	dev->chip = kzalloc(sizeof(struct rtsx_chip), GFP_KERNEL);
+	dev->chip = kzalloc(sizeof(dev->chip), GFP_KERNEL);
 	if (!dev->chip) {
 		err = -ENOMEM;
 		goto errout;