update ZFS to 2.1.11

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

diff --git a/submodules/zfsonlinux b/submodules/zfsonlinux
index 4584ec11557606a78454709bc2e67cd8d237aea0..b0c4d8ac0b3c0d7de51130b2fd1f3a63efda832c 160000 (submodule)
--- a/submodules/zfsonlinux
+++ b/submodules/zfsonlinux
@@ -1 +1 @@
-Subproject commit 4584ec11557606a78454709bc2e67cd8d237aea0
+Subproject commit b0c4d8ac0b3c0d7de51130b2fd1f3a63efda832c