Dead code elimination.

Remove the exit_main function which is never used.
Remove the exit_options array which is also unreferenced.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4213)

apps/openssl.c

@@ -267,10 +267,6 @@ int main(int argc, char *argv[])
     EXIT(ret);
 }
 
-const OPTIONS exit_options[] = {
-    {NULL}
-};
-
 static void list_cipher_fn(const EVP_CIPHER *c,
                            const char *from, const char *to, void *arg)
 {
@@ -508,11 +504,6 @@ int help_main(int argc, char **argv)
     return 0;
 }
 
-int exit_main(int argc, char **argv)
-{
-    return EXIT_THE_PROGRAM;
-}
-
 static void list_type(FUNC_TYPE ft, int one)
 {
     FUNCTION *fp;