Remove broken 70-generic kernel as well as 70-virtual

Some vendor specific images have both -virutal and
-generic kernel images, so we need to remove both versions
of the troublesome -70 kernel so that we can install -69
and let openvswitch build.

Change-Id: Id6bdbefbf6fd3b783a189c1cf2ca0923ac5c43df

nodepool/scripts/install_devstack_dependencies.sh

@@ -30,7 +30,9 @@ elif [ -f /usr/bin/apt-get ]; then
             --option "Dpkg::Options::=--force-confold" \
             --assume-yes remove linux-headers-3.2.0-70 \
             linux-headers-3.2.0-70-virtual \
-            linux-image-3.2.0-70-virtual
+            linux-image-3.2.0-70-virtual \
+            linux-headers-3.2.0-70-generic \
+            linux-image-3.2.0-70-generic
         sudo DEBIAN_FRONTEND=noninteractive apt-get \
             --option "Dpkg::Options::=--force-confold" \
             --assume-yes install --reinstall linux-headers-3.2.0-69 \