Address Watson TTS review comment (#58277)

homeassistant/components/watson_tts/tts.py

@@ -191,9 +191,7 @@ class WatsonTTSProvider(Provider):
     def get_tts_audio(self, message, language=None, options=None):
         """Request TTS file from Watson TTS."""
         response = self.service.synthesize(
-            text=message,
-            accept=self.output_format,
-            voice=options.get(CONF_VOICE, self.default_voice),
+            text=message, accept=self.output_format, voice=options[CONF_VOICE]
         ).get_result()
 
         return (CONTENT_TYPE_EXTENSIONS[self.output_format], response.content)