test-ovn: Use literal -1 instead of WAIT_ANY.
POSIX does not specify WAIT_ANY and at least MUSL libc does not define it.
@@ -983,7 +983,7 @@ wait_pid(pid_t *pids, int *n)
int status;
pid_t pid;
- pid = waitpid(WAIT_ANY, &status, 0);
+ pid = waitpid(-1, &status, 0);
if (pid < 0) {
ovs_fatal(errno, "waitpid failed");
} else if (WIFEXITED(status)) {
