package/cups-filter: add CVE trailer in patch

Since Buildroot commit [1] the patches that fixes a security
vulnerability needs to reference the fixed vulnerability.

This patch adds the relevant information to the patch header.

[1] 1167d0ff3d docs/manual: mention CVE trailer

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/cups-filters/0001-beh-backend-Use-execv-instead-of-system-CVE-2023-24805.patch

@@ -32,6 +32,7 @@ In addition, done the following fixes and improvements:
 
 - Use "static volatile int" for global variable job_canceled.
 
+CVE: CVE-2023-24805
 Upstream: https://github.com/OpenPrinting/cups-filters/commit/93e60d3df358c0ae6f3dba79e1c9684657683d89
 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
 ---