drm-shim: add __readlink_chk as identical to readlink, but with buffer overflow check
As per Linux Standard Base Core Specification 4.0, __readlink_chk display value of a symbolic link, with buffer overflow checking.
if size > buflen, __chk_fail() is called, which terminates the function for buffer overflow.
Signed-off-by: Max Lee endlesspring@chromium.org
Edited by Max Lee