scrut(1): fixes failing write test

src/scrut.c

@@ -82,7 +82,7 @@ int main(int argc, char *argv[]) {
 		struct stat buf;
 
 #ifdef __OpenBSD__
-		if (unveil(*argv, "r") == -1) {
+		if (unveil(*argv, "rw") == -1) {
 			perror(program_name);
 			return EX_OSERR;
 		}