CLSA-2026-1776769506 libexif: Fix of 3 CVEs

CVE-2026-32775: fix buffer overwrite via integer underflow in MakerNote entry value handling - CVE-2026-40385: fix unsigned 32-bit integer overflow in Nikon MakerNote handling - CVE-2026-40386: fix integer underflow in Fuji/Olympus MakerNote size checks...