fix a few debugging problems

jedi/_compatibility.py

@@ -168,6 +168,8 @@ def u(string):
     have to cast back to a unicode (and we now that we always deal with valid
     unicode, because we check that in the beginning).
     """
-    if not is_py3k and not isinstance(string, unicode):
+    if is_py3k:
+        return str(string)
+    elif not isinstance(string, unicode):
         return unicode(str(string), 'UTF-8')
     return string

jedi/debug.py

@@ -48,7 +48,7 @@ def warning(*args):
 def speed(name):
     if debug_function and enable_speed:
         now = time.time()
-        debug_function(SPEED, 'speed: ' + '%s %s' % (u(name), now - start_time))
+        debug_function(SPEED, 'speed: ' + '%s %s' % (name, now - start_time))
 
 
 def print_to_stdout(level, str_out):