Make non-executed tests that are not in the allow list an error

 * Turn the warnings produced when finding non-executed tests that
   are not in the allow list into errors.

Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
diff --git a/tests/scripts/analyze_outcomes.py b/tests/scripts/analyze_outcomes.py
index 4f381bd..0bdfcf9 100755
--- a/tests/scripts/analyze_outcomes.py
+++ b/tests/scripts/analyze_outcomes.py
@@ -63,7 +63,10 @@
                 results.warning('Test case not executed: {}', key)
         elif hits != 0 and key in allow_list:
             # Test Case should be removed from the allow list.
-            results.warning('Allow listed test case was executed: {}', key)
+            if full_coverage:
+                results.error('Allow listed test case was executed: {}', key)
+            else:
+                results.warning('Allow listed test case was executed: {}', key)
 
 def analyze_outcomes(outcomes, args):
     """Run all analyses on the given outcome collection."""