free NULL cleanup 5a

Don't check for NULL before calling a free routine.  This gets X509_.*free:
    x509_name_ex_free X509_policy_tree_free X509_VERIFY_PARAM_free
    X509_STORE_free X509_STORE_CTX_free X509_PKEY_free
    X509_OBJECT_free_contents X509_LOOKUP_free X509_INFO_free

Reviewed-by: Richard Levitte <levitte@openssl.org>

demos/spkigen.c

@@ -166,7 +166,6 @@ EVP_PKEY *pkey;
     pk = NULL;
     ok = 1;
  err:
-    if (pk != NULL)
-        X509_PUBKEY_free(pk);
+    X509_PUBKEY_free(pk);
     return (ok);
 }