Some ABSL_RAW_LOG statements print off_t values by casting them to
uintmax_t. However, POSIX says off_t is signed [1], so intmax_t is more
appropriate. Replace casts and format specifiers as needed.

[1] https://pubs.opengroup.org/onlinepubs/009696899/basedefs/sys/types.h.html#:~:text=off_t%20shall,%20types%2e

PiperOrigin-RevId: 461684406
Change-Id: I09ec1a3ba49cd688670618797943a84bc48dba3e