thunderbolt: property: Fix a NULL pointer dereference

In case kzalloc fails, the fix releases resources and returns
-ENOMEM to avoid the NULL pointer dereference.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/property.c

@@ -548,6 +548,11 @@ int tb_property_add_data(struct tb_property_dir *parent, const char *key,
 
 	property->length = size / 4;
 	property->value.data = kzalloc(size, GFP_KERNEL);
+	if (!property->value.data) {
+		kfree(property);
+		return -ENOMEM;
+	}
+
 	memcpy(property->value.data, buf, buflen);
 
 	list_add_tail(&property->list, &parent->properties);