suppress warnings about easch <applet>_main() having

no preceding prototype

miscutils/mt.c

@@ -50,6 +50,7 @@ static const struct mt_opcodes opcodes[] = {
 	{0, 0}
 };
 
+int mt_main(int argc, char **argv);
 int mt_main(int argc, char **argv)
 {
 	const char *file = "/dev/tape";