nstree: fix func. parameter kernel-doc warnings

Use the correct parameter name ("__ns") for function parameter kernel-doc
to avoid 3 warnings:

Warning: include/linux/nstree.h:68 function parameter '__ns' not described in 'ns_tree_add_raw'
Warning: include/linux/nstree.h:77 function parameter '__ns' not described in 'ns_tree_add'
Warning: include/linux/nstree.h:88 function parameter '__ns' not described in 'ns_tree_remove'

Fixes: 885fc8a ("nstree: make iterator generic")
Signed-off-by: Randy Dunlap <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: rddunlap

include/linux/nstree.h

@@ -61,7 +61,7 @@ static inline void __ns_tree_add(struct ns_common *ns, struct ns_tree_root *ns_t
 
 /**
  * ns_tree_add_raw - Add a namespace to a namespace
- * @ns: Namespace to add
+ * @__ns: Namespace to add
  *
  * This function adds a namespace to the appropriate namespace tree
  * without assigning a id.
@@ -70,7 +70,7 @@ static inline void __ns_tree_add(struct ns_common *ns, struct ns_tree_root *ns_t
 
 /**
  * ns_tree_add - Add a namespace to a namespace tree
- * @ns: Namespace to add
+ * @__ns: Namespace to add
  *
  * This function assigns a new id to the namespace and adds it to the
  * appropriate namespace tree and list.
@@ -81,7 +81,7 @@ static inline void __ns_tree_add(struct ns_common *ns, struct ns_tree_root *ns_t
 
 /**
  * ns_tree_remove - Remove a namespace from a namespace tree
- * @ns: Namespace to remove
+ * @__ns: Namespace to remove
  *
  * This function removes a namespace from the appropriate namespace
  * tree and list.