Update libyang

This is needed for a warning-free build.

Change-Id: I1a1e143b2da5613497e92eb9c05fdce78328eab2
diff --git a/submodules/libyang b/submodules/libyang
index 46ba580..c92e2e0 160000
--- a/submodules/libyang
+++ b/submodules/libyang
@@ -1 +1 @@
-Subproject commit 46ba5802b70b6cf1e9dfb03140065d6c9cd57c8b
+Subproject commit c92e2e03db17f0f8920997a995f5406da6917cb8