Fix warning when compiling with no-ec2m
Fix warning when compiling with no-ec2m

EC_KEY_set_public_key_affine_coordinates was using some variables that only
apply if OPENSSL_NO_EC2M is not defined.

Reviewed-by: Viktor Dukhovni <86faeb3e05561b856666236e198c27e698275e82@openssl.org>

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl