Add missing compute service tags to volume API tests

This commit adds the missing service tags to the volume api tests.

Partially implements bp add-service-tags

Change-Id: I6f403aab25ed5432bb91a7c8ee1801293ce91c9a
diff --git a/tempest/api/volume/test_volumes_negative.py b/tempest/api/volume/test_volumes_negative.py
index a8b0a8d..bc5b1dc 100644
--- a/tempest/api/volume/test_volumes_negative.py
+++ b/tempest/api/volume/test_volumes_negative.py
@@ -154,6 +154,7 @@
         self.assertRaises(exceptions.NotFound, self.client.delete_volume, '')
 
     @test.attr(type=['negative', 'gate'])
+    @test.services('compute')
     def test_attach_volumes_with_nonexistent_volume_id(self):
         srv_name = data_utils.rand_name('Instance-')
         resp, server = self.servers_client.create_server(srv_name,
diff --git a/tempest/api/volume/test_volumes_snapshots.py b/tempest/api/volume/test_volumes_snapshots.py
index 6294cd9..26316d2 100644
--- a/tempest/api/volume/test_volumes_snapshots.py
+++ b/tempest/api/volume/test_volumes_snapshots.py
@@ -63,6 +63,7 @@
                 self.assertEqual(params[key], snap[key], msg)
 
     @test.attr(type='gate')
+    @test.services('compute')
     def test_snapshot_create_with_volume_in_use(self):
         # Create a snapshot when volume status is in-use
         # Create a test instance