m_getfld.c: Use intmax_t and PRIdMAX to printf off_t values.
m_getfld.c: Use intmax_t and PRIdMAX to printf off_t values.

Compiling for ISO C90 prohibits casting to long long and printing with
"%lld", and printing as "%ld" is wrong on Mac OS where David reports
off_t is long long.

mcr/nmh,mcr/nmh