Update submodule for driver/linux.

Update linux driver to clear RX buffer if message is not deliverable.

Change-Id: I74f3c0199abfb6d741046a45692e8c7ba9acb97e
diff --git a/driver/linux b/driver/linux
index 18f08a6..39fdefd 160000
--- a/driver/linux
+++ b/driver/linux
@@ -1 +1 @@
-Subproject commit 18f08a63274fd788d4937b221405e782406b6d6a
+Subproject commit 39fdefde0565df7811cf4bb98e6185e624a43603