sq-poller: fix crash when inventory is not mapping

Signed-off-by: Claudio Lorina <[email protected]>

Author: claudiolor

suzieq/poller/controller/utils/inventory_utils.py

@@ -106,6 +106,11 @@ def find_error(
     if not inventory:
         raise InventorySourceError('The inventory is empty')
 
+    if not isinstance(inventory, dict):
+        raise InventorySourceError(
+            'Expected mapping instead of list. Check the docs to know how to '
+            'build the inventory file')
+
     try:
         inv_model = InventoryModel(**inventory)
     except ValidationError as e: