python: Fixup incorrect syntax in PyBind argument handler

Change-Id: Ie81104d89b554795ec1020d5ce4edcf28795eda8
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11511
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

src/python/m5/util/pybind.py

@@ -63,7 +63,7 @@ class PyBindMethod(PyBindExport):
     def _conv_arg(self, value):
         if isinstance(value, bool):
             return "true" if value else "false"
-        elif isinstance(value, float, int):
+        elif isinstance(value, (float, int)):
             return repr(value)
         else:
             raise TypeError("Unsupported PyBind default value type")