GFS2: Use RB_CLEAR_NODE() rather than rb_init_node()

gfs2 calls RB_EMPTY_NODE() to check if nodes are not on an rbtree.
The corresponding initialization function is RB_CLEAR_NODE().
rb_init_node() was never clearly defined and is going away.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/rgrp.c

@@ -453,7 +453,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
 	if (!res)
 		error = -ENOMEM;
 
-	rb_init_node(&res->rs_node);
+	RB_CLEAR_NODE(&res->rs_node);
 
 	down_write(&ip->i_rw_mutex);
 	if (ip->i_res)
@@ -486,7 +486,7 @@ static void __rs_deltree(struct gfs2_inode *ip, struct gfs2_blkreserv *rs)
 	rgd = rs->rs_rbm.rgd;
 	trace_gfs2_rs(ip, rs, TRACE_RS_TREEDEL);
 	rb_erase(&rs->rs_node, &rgd->rd_rstree);
-	rb_init_node(&rs->rs_node);
+	RB_CLEAR_NODE(&rs->rs_node);
 	BUG_ON(!rgd->rd_rs_cnt);
 	rgd->rd_rs_cnt--;