Simplify the PCT for RSA and ECDSA

Could be squashed.

• cipher/ecc.c (test_keys_fips): Simplify to accept key in SEXP format (nist_generate_key): Skip call to test keys (ecc_generate): Call test keys in FIPS mode later, when we have complete SEXP key structure.
• cipher/rsa.c (test_keys_fips): Simplify to accept key in SEXP format (generate_fips): Skip selftest at this stage (rsa_generate): Test the keys later when we already have key in SEXP format --

• Signed-off-by: Jakub Jelen <jjelen@redhat.com>