Bug#1142687: libcupsfilters: CVE-2026-64612 - fix e8888af31419 (in 2.2.0) applies cleanly to 2.1.1-2 and 2.0.0-3+deb13u1

[Sumit Verma]

Small correction to my previous mail: the file the fix touches is
cupsfilters/image-png.c, not "cupsfilter/image-png.c". The result is
the same: it applies cleanly to both versions.

Regards