Remove dosfstools-dbg package from ubuntu installs

This packages was added in [1] without an explanation of why the
debug symbols are required. The symbols package is not built for
bionic [2] so we remove it allowing the common vars file to work
for both Xenial and Bionic releases.

[1] e771983f2c
[2] http://archive.ubuntu.com/ubuntu/pool/main/d/dosfstools/dosfstools_4.1-1.dsc

Change-Id: I283628e6d42c6708934975d272712353472e066b

vars/ubuntu-16.04.yml

@@ -90,7 +90,6 @@ nova_compute_kvm_distro_packages:
   - vlan
   - nfs-common
   - dosfstools
-  - dosfstools-dbg
   - multipath-tools
   - qemu-system
   - qemu-system-arm
@@ -113,7 +112,6 @@ nova_compute_kvm_packages_to_symlink:
 nova_compute_lxd_distro_packages:
   - bridge-utils
   - dosfstools
-  - dosfstools-dbg
   - genisoimage
   - kpartx
   - lxd
@@ -136,7 +134,6 @@ nova_compute_powervm_distro_packages:
   - vlan
   - nfs-common
   - dosfstools
-  - dosfstools-dbg
   - multipath-tools
   - pvm-novalink