Make the dumping of dmesg configurable

From 36281407d2f99ed8deb29a4f4c3d94506c1ccec5 Mon Sep 17 00:00:00 2001
From: Juerg Haefliger <juerg.haefliger@hp.com>
Date: Tue, 6 May 2014 07:44:45 +0000
Subject: [PATCH] Make the dumping of dmesg configurable

Dumping the dmesg buffer has shown to be problematic when kernels
change. This patch introduces a new config variable that can turn
the dmesg dump off.  The default behaviour unchanged, i.e., the
dmesg buffer is dumped.

Signed-off-by: Louis Bouchard <louis.bouchard@ubuntu.com>