anv: check the return value of anv_execbuf_add_bo_bitset()

anv: check the return value of anv_execbuf_add_bo_bitset()

Because anv_execbuf_add_bo_bitset() calls anv_execbuf_add_bo(), which
can fail if its memory allocations fail.

I have seen dEQP tests exercising memory allocation failures during
anv_execbuf_add_bo(), but I don't think the path coming from
add_bo_biset() was specifically exercised. Anyway, add the error check
just in case.

v2: Rebase.

Cc: mesa-stable
Reviewed-by: Ivan Briano <ivan.briano@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20703>
(cherry picked from commit 3d37950fd9ddc7b43f06b4a5fa710fb7333978ce)