From: Pavel Emelyanov <xemul@openvz.org>

The function in question returns ERR_PTR-s to indicate the
error, while the caller checks for return value to be NULL.

Found during testing the OpenVZ kernel with pid namespaces.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/pid.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN kernel/pid.c~pid-namespaces-allow-cloning-of-new-namespace-fix-check-for-return-value-of-create_pid_namespace kernel/pid.c
--- a/kernel/pid.c~pid-namespaces-allow-cloning-of-new-namespace-fix-check-for-return-value-of-create_pid_namespace
+++ a/kernel/pid.c
@@ -544,7 +544,7 @@ struct pid_namespace *copy_pid_ns(unsign
 		goto out_put;
 
 	new_ns = create_pid_namespace(old_ns->level + 1);
-	if (new_ns != NULL)
+	if (!IS_ERR(new_ns))
 		new_ns->parent = get_pid_ns(old_ns);
 
 out_put:
_