[RBTREE] Update eventpoll.c to use rb_parent() accessor macro.

/* Special initialization for the rb-tree node to detect linkage */

static inline void ep_rb_initnode(struct rb_node *n)

{

	n->rb_parent = n;

	rb_set_parent(n, n);

}

/* Removes a node from the rb-tree and marks it for a fast is-linked check */

static inline void ep_rb_erase(struct rb_node *n, struct rb_root *r)

{

	rb_erase(n, r);

	n->rb_parent = n;

	rb_set_parent(n, n);

}

/* Fast check to verify that the item is linked to the main rb-tree */

static inline int ep_rb_linked(struct rb_node *n)

{

	return n->rb_parent != n;

	return rb_parent(n) != n;

}

/*