xserver-xorg: fix CVE-2021-3472

Insufficient checks on the lengths of the XInput extension
ChangeFeedbackControl request can lead to out of bounds memory accesses
in the X server.

References:
https://nvd.nist.gov/vuln/detail/CVE-2021-3472

Upstream patches:
https://gitlab.freedesktop.org/xorg/xserver/-/commit/7aaf54a1884f71dc363f0b884e57bcb67407a6cd



Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 6fec5fea)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>