RT3543: Remove #ifdef LINT

I also replaced some exit/return wrappers in various
programs (from main) to standardize on return.

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

apps/req.c

@@ -1773,9 +1773,6 @@ static int genpkey_cb(EVP_PKEY_CTX *ctx)
 	if (p == 3) c='\n';
 	BIO_write(b,&c,1);
 	(void)BIO_flush(b);
-#ifdef LINT
-	p=n;
-#endif
 	return 1;
 	}