platform/chrome: cros_ec_vbc: Constify 'struct bin_attribute'

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Tzung-Bi Shih <[e-mail]>

drivers/platform/chrome/cros_ec_vbc.c

···
 #define DRV_NAME "cros-ec-vbc"
 
 static ssize_t vboot_context_read(struct file *filp, struct kobject *kobj,
-				  struct bin_attribute *att, char *buf,
+				  const struct bin_attribute *att, char *buf,
 				  loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);
···
 }
 
 static ssize_t vboot_context_write(struct file *filp, struct kobject *kobj,
-				   struct bin_attribute *attr, char *buf,
+				   const struct bin_attribute *attr, char *buf,
 				   loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);
···
 	return data_sz;
 }
 
-static BIN_ATTR_RW(vboot_context, 16);
+static const BIN_ATTR_RW(vboot_context, 16);
 
-static struct bin_attribute *cros_ec_vbc_bin_attrs[] = {
+static const struct bin_attribute *const cros_ec_vbc_bin_attrs[] = {
 	&bin_attr_vboot_context,
 	NULL
 };
 
 static const struct attribute_group cros_ec_vbc_attr_group = {
 	.name = "vbc",
-	.bin_attrs = cros_ec_vbc_bin_attrs,
+	.bin_attrs_new = cros_ec_vbc_bin_attrs,
 };
 
 static int cros_ec_vbc_probe(struct platform_device *pd)