tests: cleanup unused variable

The result of the load_module() call is not used, because the call is
expected to fail.

No functional change.

Closes: #173
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>

Author: jktjkt

tests/test_context.py

@@ -174,7 +174,7 @@ def get_module_invalid_clb(mod_name, *_):
 
             ctx.external_module_loader.set_module_data_clb(get_module_invalid_clb)
             with self.assertRaises(LibyangError):
-                mod = ctx.load_module("yolo-nodetypes")
+                ctx.load_module("yolo-nodetypes")
 
             ctx.external_module_loader.set_module_data_clb(get_module_valid_clb)
             mod = ctx.load_module("yolo-nodetypes")