ceph: Removing any error while trying to find 'data_pool'

If we are unable to get a default ceph data pool name,
script won't be throwing an error.

Signed-off-by: Arun Kumar Mohan <amohan@redhat.com>

cluster/examples/kubernetes/ceph/create-external-cluster-resources.py

@@ -285,8 +285,6 @@ def get_cephfs_data_pool_details(self):
             self._arg_parser.cephfs_filesystem_name = str(json_out[0]['name'])
             matching_json_out = json_out[0]
         if type(matching_json_out['data_pools']) == list:
-            if len(matching_json_out['data_pools']) == 0:
-                raise ExecutionFailureException("No 'data_pools' found.")
             # if the user has already provided data-pool-name,
             # through --cephfs-data-pool-name
             if self._arg_parser.cephfs_data_pool_name:
@@ -298,6 +296,7 @@ def get_cephfs_data_pool_details(self):
                             self._arg_parser.cephfs_data_pool_name,
                             [str(x) for x in matching_json_out['data_pools']]))
             else:
+                # if nothing is provided, try to find a default data pool name
                 self._arg_parser.cephfs_data_pool_name = str(
                     matching_json_out['data_pools'][0])
             if len(matching_json_out['data_pools']) > 1: