ostbuild: Fix error message for unknown builtin

src/ostbuild/pyostbuild/builtins.py

@@ -47,7 +47,10 @@ def register(builtin):
     _all_builtins[builtin.name] = builtin
 
 def get(name):
-    return _all_builtins.get(name)()
+    builtin = _all_builtins.get(name)
+    if builtin is not None:
+        return builtin()
+    return None
 
 def get_all():
     return _all_builtins.itervalues()

src/ostbuild/pyostbuild/main.py

@@ -44,7 +44,7 @@ def main(args):
     else:
         builtin = builtins.get(args[0])
         if builtin is None:
-            print "error: Unknown builtin '%s'" % (args[1], )
+            print "error: Unknown builtin '%s'" % (args[0], )
             return usage(1)
         return builtin.execute(args[1:])