update to lxcfs-4.0.12

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

diff --git a/lxcfs b/lxcfs
index 6a312987219675ed9f5fa1223bc1647858023357..310cdb706cf1bc2856cfcad84df9ce82a833082b 160000 (submodule)
--- a/lxcfs
+++ b/lxcfs
@@ -1 +1 @@
-Subproject commit 6a312987219675ed9f5fa1223bc1647858023357
+Subproject commit 310cdb706cf1bc2856cfcad84df9ce82a833082b