Currently running KVM/QEMU with vdso enabled trips a segfault on
vdso access inside the virtual machine. Force the default vdso
setting off to workaround this issue. It is our expecation to
revert this once we have figured out the root issue.

CVE-2017-5754
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>