etnaviv/drm: only print out fence error on non timeout

etnaviv/drm: only print out fence error on non timeout

While looking at the traces emitted by chromium, I saw a lot of those
errors. But looking at the value of ns, it is 0, so it's probably just
the application checking whether work is done or not. Not much point
in printing out an error.

v2: check ret value (Christian)
    check both timeout codes (Lionel)

Signed-off-by: Lionel Landwerlin <llandwerlin@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9875>