update ZFS to 2.2.3

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/submodules/zfsonlinux b/submodules/zfsonlinux
index 81d11761c3a2d325b1b434247894365119ce22eb..6c9ff9b992b46b2ba7c7b8ab9b5eaf35fff17158 160000 (submodule)
--- a/submodules/zfsonlinux
+++ b/submodules/zfsonlinux
@@ -1 +1 @@
-Subproject commit 81d11761c3a2d325b1b434247894365119ce22eb
+Subproject commit 6c9ff9b992b46b2ba7c7b8ab9b5eaf35fff17158