Fix typo in exptest.c.

crypto/bn/exptest.c

@@ -163,7 +163,7 @@ int main(int argc, char *argv[])
 		  	{
 			if (BN_cmp(r_simple,r_mont) != 0)
 				printf("\nsimple and mont results differ\n");
-			if (BN_cmp(r_simple,r_mont) != 0)
+			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");