gui: fixes from Marek's comments

qubes/ext/gui.py

@@ -125,7 +125,7 @@ class GUI(qubes.ext.Extension):
     @qubes.ext.handler('domain-feature-pre-set:keyboard-layout')
     def on_feature_pre_set(self, subject, event, feature, value, oldvalue=None):
         untrusted_xkb_layout = value.split('+')
-        if not len(untrusted_xkb_layout) == 3:
+        if len(untrusted_xkb_layout) != 3:
             raise qubes.exc.QubesValueError("Invalid number of parameters")
 
         untrusted_layout = untrusted_xkb_layout[0]
@@ -137,7 +137,7 @@ class GUI(qubes.ext.Extension):
 
         if not untrusted_layout.isalpha():
             raise qubes.exc.QubesValueError("Invalid layout provided")
-        if not bool(re.match(re_variant, untrusted_variant)):
+        if not re.match(re_variant, untrusted_variant):
             raise qubes.exc.QubesValueError("Invalid variant provided")
-        if not bool(re.match(re_options, untrusted_options)):
+        if not re.match(re_options, untrusted_options):
             raise qubes.exc.QubesValueError("Invalid options provided")