egl: zero is a valid fd

egl: zero is a valid fd

We shouldn't be using RETURN_EGL_EVAL() for eglDupNativeFenceFDANDROID()
return, as (while perhaps unlikely) zero is a valid fd.  The error case
for EGL_NO_NATIVE_FENCE_FD_ANDROID is already handled in egl_dri2.c
(dri2_dup_native_fence_fd()) so just use RETURN_EGL_SUCCESS() instead.

Also fix ret type.

Fixes: 0201f01dc4e ("egl: add EGL_ANDROID_native_fence_sync")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11202>