python: Fix call bug in @cxxMethod when override is True
python: Fix call bug in @cxxMethod when override is True

Change-Id: Ifa9efbd329fd01eb13100bc6690e651df2c12294
Signed-off-by: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Reviewed-by: Javier Setoain <8a74c80c43facd01396beb11de48539de054b1e9@arm.com>
Reviewed-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11514
Reviewed-by: Jason Lowe-Power <68c46a606457643eab92053c1c05574abb26f861@lowepower.com>
Maintainer: Jason Lowe-Power <68c46a606457643eab92053c1c05574abb26f861@lowepower.com>

TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,gem5/gem5,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu