openac: Make sure path is null-terminated.

src/openac/openac.c

@@ -300,6 +300,7 @@ int main(int argc, char **argv)
 					if (*optarg == '/')	/* absolute pathname */
 					{
 						strncpy(path, optarg, BUF_LEN);
+						path[BUF_LEN-1] = '\0';
 					}
 					else			/* relative pathname */
 					{