pid namespaces: rename child_reaper() function

Rename the child_reaper() function to task_child_reaper() to be similar to
other task_* functions and to distinguish the function from 'struct
pid_namspace.child_reaper'.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzel <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index d10cb5f..aea13ec 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -44,7 +44,7 @@
 	return tsk->nsproxy->pid_ns;
 }
 
-static inline struct task_struct *child_reaper(struct task_struct *tsk)
+static inline struct task_struct *task_child_reaper(struct task_struct *tsk)
 {
 	return init_pid_ns.child_reaper;
 }