Make i2d_ASN1_OBJECT() return -1 on error

Make i2d_ASN1_OBJECT() return -1 on error

This is what the (not quite appropriately) referenced ASN1_item_i2d()
page documents for errors, matches what the RETURN VALUE section has
been documenting for ages, matches BoringSSL, it's the usal behavior
for i2d_*. It's also what OpenSSL (of course incorrectly) documents.

discussed with jsing