Make nova-lvm run in check on libvirt changes and compute API tests

This changes the nova-lvm job to run in the check queue on libvirt
driver changes only, and only runs the tempest compute API tests
to save time since we don't need to run things like the cinder,
glance, neutron etc API tests.

Once we're comfortable with the stability of this job we can
make it voting and gating.

This is in response to bug 1771700 which could have been prevented
if we were gating on the nova-lvm job on libvirt changes.

Change-Id: Ieaf00bcb6cb885e544d05b6f7276b6470b123258
Related-Bug: #1771700

devstack/tempest-dsvm-lvm-rc

@@ -33,6 +33,11 @@
 r="^(?!.*"
 r="$r(?:.*\[.*\bslow\b.*\])"
 
+# Only run compute API tests. The ! here looks confusing but it's to negate
+# the ! at the beginning of the regex since the rest of this is meant to be
+# a backlist.
+r="$r|(?!.*api.compute.*)"
+
 # NOTE(mriedem): resize of non-volume-backed lvm instances does not yet work
 # tempest.api.compute.admin.test_migrations.MigrationsAdminTest.test_list_migrations_in_flavor_resize_situation
 r="$r|(?:.*id\-1b512062\-8093\-438e\-b47a\-37d2f597cd64.*)"