scripts: twister: Process KeyboardInterrupt Hardening

If you interrupt process() operation, we want Twister
to exit as gracefully as it can. This avoids the
UnboundLocalError that could appear e.g.
when interrupting the operation via SIGINT.

Signed-off-by: Lukasz Mrugala <lukaszx.mrugala@intel.com>

scripts/pylib/twister/twisterlib/runner.py

@@ -615,6 +615,9 @@ class ProjectBuilder(FilterBuilder):
 
 
     def process(self, pipeline, done, message, lock, results):
+        next_op = None
+        additionals = {}
+
         op = message.get('op')
 
         self.instance.setup_handler(self.env)
@@ -772,8 +775,6 @@ class ProjectBuilder(FilterBuilder):
                     done.put(self.instance)
                     self.report_out(results)
 
-                next_op = None
-                additionals = {}
                 if not self.options.coverage:
                     if self.options.prep_artifacts_for_testing:
                         next_op = 'cleanup'