Add missing checks for BN_mod_exp_{non,}ct()

Someone added a few more functions to test, but forgot to check their
results, so if they would not do the expected thing that would only be
noticed if one of the already tested functions would break.

Author: tb

src/regress/lib/libcrypto/bn/bn_mod_exp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: bn_mod_exp.c,v 1.6 2022/12/03 08:05:52 tb Exp $	*/
+/*	$OpenBSD: bn_mod_exp.c,v 1.7 2022/12/03 08:21:38 tb Exp $	*/
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -157,18 +157,20 @@ main(int argc, char *argv[])
 		}
 
 		if (BN_cmp(r_simple, r_mont) != 0 ||
+		    BN_cmp(r_simple, r_mont_const) ||
 		    BN_cmp(r_simple, r_recp) != 0 ||
-		    BN_cmp(r_simple, r_mont_const) != 0) {
+		    BN_cmp(r_simple, r_mont_ct) != 0 ||
+		    BN_cmp(r_simple, r_mont_nonct) != 0) {
 			if (BN_cmp(r_simple, r_mont) != 0)
 				printf("\nsimple and mont results differ\n");
 			if (BN_cmp(r_simple, r_mont_const) != 0)
 				printf("\nsimple and mont const time results differ\n");
 			if (BN_cmp(r_simple, r_recp) != 0)
 				printf("\nsimple and recp results differ\n");
-			if (BN_cmp(r_mont, r_mont_ct) != 0)
-				printf("\nmont_ct and mont results differ\n");
-			if (BN_cmp(r_mont_ct, r_mont_nonct) != 0)
-				printf("\nmont_ct and mont_nonct results differ\n");
+			if (BN_cmp(r_simple, r_mont_ct) != 0)
+				printf("\nsimple and mont results differ\n");
+			if (BN_cmp(r_simple, r_mont_nonct) != 0)
+				printf("\nsimple and mont_nonct results differ\n");
 
 			printf("a (%3d) = ", BN_num_bits(a));
 			BN_print_fp(stdout, a);