Use tempest.lib data_utils - compute

Tempest has duplicated modules of data_utils, one is tempest.lib and
the other is tempest.common. The difference is tempest.common module
refers to the config option resources_prefix. And the option is marked
as deprecated already. So it is nice to replace the calls with tempest.lib
one.

Change-Id: Idfa9824d14a1e5e4291fcb70bb2c00caf9083d67
diff --git a/tempest/api/compute/servers/test_server_group.py b/tempest/api/compute/servers/test_server_group.py
index 6679b58..69d7897 100644
--- a/tempest/api/compute/servers/test_server_group.py
+++ b/tempest/api/compute/servers/test_server_group.py
@@ -14,7 +14,7 @@
 #    under the License.
 
 from tempest.api.compute import base
-from tempest.common.utils import data_utils
+from tempest.lib.common.utils import data_utils
 from tempest.lib import decorators
 from tempest import test