drm/tegra: fix error return code in gr2d_submit()

Fix to return -ENOENT in the host1x_bo lookup error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>