* cipher/pubkey.c (_gcry_pk_encrypt): Fail if algo is disabled
  (_gcry_pk_decrypt): Ditto.
  (_gcry_pk_sign): Ditto.
  (_gcry_pk_sign_md): Ditto.
  (_gcry_pk_verify): Ditto.
  (_gcry_pk_verify_md): Ditto.
  (_gcry_pk_testkey): Ditto.
  (_gcry_pk_get_nbits): Ditto.
  (_gcry_pk_get_curve): Ditto.
* tests/basic.c (check_pubkey): Test also other API in FIPS mode to
  verify they fail as expected.