LibC: Missing varargs cleanup in ioctl

Author: https://github.com/bgianfo
Commit: 9ffbe03bdb
Pull-request: https://github.com/SerenityOS/serenity/pull/3184
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/bugaevc

Libraries/LibC/ioctl.cpp

@@ -38,6 +38,7 @@ int ioctl(int fd, unsigned request, ...)
     va_start(ap, request);
     unsigned arg = va_arg(ap, unsigned);
     int rc = syscall(SC_ioctl, fd, request, arg);
+    va_end(ap);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 }