tests/sleeptest: Make use of the new accessors

Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

tests/sleeptest/sleeptest.py

@@ -27,13 +27,18 @@ class sleeptest(test.Test):
     Example test for avocado.
     """
 
+    def setup(self):
+        """
+        If no config was provided, give self.params.sleep_length a default.
+        """
+        self.params.set_default('sleep_length', 1.0)
+
     def action(self):
         """
         Sleep for length seconds.
         """
-        length = self.params.get('sleep_length', 1.0)
-        self.log.debug("Sleeping for %.2f seconds", length)
-        time.sleep(length)
+        self.log.debug("Sleeping for %.2f seconds", self.params.sleep_length)
+        time.sleep(self.params.sleep_length)
 
 
 if __name__ == "__main__":