CVE-2026-37555: fix integer overflow in src/ima_adpcm.c when computing
sf.frames from samplesperblock * blocks; pre-cast samplesperblock to
sf_count_t before the multiplication so a crafted WAV/AIFF audio file
cannot trigger a heap buffer overflow (lifted verbatim from upstream
libsndfile 0e1d2664 / RH RHEL-174543)