cve-check.bbclass: CVE-2014-2524 / readline v5.2

cve-check.bbclass: CVE-2014-2524 / readline v5.2

Contrary to the CVE report, the vulnerable trace functions
don't exist in readline v5.2 (which we keep for GPLv2+
purposes), they were added in readline v6.0 only - let's
whitelist that CVE in order to avoid false positives.

See also the discussion in
 https://patchwork.openembedded.org/patch/81765/

(From OE-Core rev: b881a288eec598002685f68da80a24e0478fa496)

(From OE-Core rev: b4498a6b734661fdfe3ff4e0a9850e796b72005c)

Signed-off-by: André Draszik <adraszik@tycoint.com>
Reviewed-by: Lukasz Nowak <lnowak@tycoint.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>