drm/tegra: Remove surplus else after return

else is not generally useful after return

Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230626143331.640454-2-suijingfeng@loongson.cn