loader,glx,egl,vl,d3d: loader_get_user_preferred_fd() function to return original_fd

loader,glx,egl,vl,d3d: loader_get_user_preferred_fd() function to return original_fd

v1: return original_fd in loader_get_user_preferred_fd() (Pierre-Eric)
v2: fix *original_id crash for android, haiku... (Pierre-Eric)
    remove extra comment (Pierre-Eric)
v2: also return render fd in case of original_fd passed is NULL (Pierre-Eric)

Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohanmarimuthu@amd.com>
Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13422>