[PATCH rtems-docs] c-user/chains: Correct iteration example code

[Kinsey Moore]

Casting the node returned by rtems_chain_head is incorrect. That node is
owned by the control structure and use of it post-cast could cause
memory corruption.
---
 c-user/chains.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/c-user/chains.rst b/c-user/chains.rst
index f518ef4..e791d10 100644
--- a/c-user/chains.rst
+++ b/c-user/chains.rst
@@ -193,6 +193,10 @@ placed on another chain:
         rtems_chain_initialize_empty (out);
 
         node = rtems_chain_head (chain);
+
+        /* The node returned by rtems_chain_head() is owned by the chain */
+        node = node->next;
+
         while (!rtems_chain_is_tail (chain, node))
         {
             bar = (foo*) node;
-- 
2.30.2