Update dxcommon to latest version.

This is to get exported.sh updates.

diff --git a/common b/common
index 2e5b48374d80959256e535bc1973f032158bde9e..84dd06463916fbf857351fbaba4ea33e1e056460 160000 (submodule)
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit 2e5b48374d80959256e535bc1973f032158bde9e
+Subproject commit 84dd06463916fbf857351fbaba4ea33e1e056460