samples/kobject: Replace foo_ktype's default_attrs field with groups

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace foo_ktype's default_attrs field with
default_groups and use the ATTRIBUTE_GROUPS macro to create
foo_default_groups.

This patch was tested by loading the kset-example module and verifying
that the sysfs files for the attributes in the default group were
created.

Signed-off-by: Kimberly Brown <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

samples/kobject/kset-example.c

···
 	&bar_attribute.attr,
 	NULL,	/* need to NULL terminate the list of attributes */
 };
+ATTRIBUTE_GROUPS(foo_default);
 
 /*
  * Our own ktype for our kobjects.  Here we specify our sysfs ops, the
···
 static struct kobj_type foo_ktype = {
 	.sysfs_ops = &foo_sysfs_ops,
 	.release = foo_release,
-	.default_attrs = foo_default_attrs,
+	.default_groups = foo_default_groups,
 };
 
 static struct kset *example_kset;