[media] stb6100: fix buffer length check in stb6100_write_reg_range()

We are checking sizeof() the wrong variable!

Signed-off-by: Alexander Shiyan <[e-mail]>
Signed-off-by: Michael Krufky <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb-frontends/stb6100.c

···
 		.len	= len + 1
 	};
 
-	if (1 + len > sizeof(buf)) {
+	if (1 + len > sizeof(cmdbuf)) {
 		printk(KERN_WARNING
 		       "%s: i2c wr: len=%d is too big!\n",
 		       KBUILD_MODNAME, len);