[media] sn9c20x: fix checkpatch warning: sizeof cmatrix should be sizeof(cmatrix)

Signed-off-by: Morgan Phillips <winter2718@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/gspca/sn9c20x.c

@@ -1297,7 +1297,7 @@ static void set_cmatrix(struct gspca_dev *gspca_dev,
 	s32 hue_coord, hue_index = 180 + hue;
 	u8 cmatrix[21];
 
-	memset(cmatrix, 0, sizeof cmatrix);
+	memset(cmatrix, 0, sizeof(cmatrix));
 	cmatrix[2] = (contrast * 0x25 / 0x100) + 0x26;
 	cmatrix[0] = 0x13 + (cmatrix[2] - 0x26) * 0x13 / 0x25;
 	cmatrix[4] = 0x07 + (cmatrix[2] - 0x26) * 0x07 / 0x25;