zfs: Update test format strings to match variable typtes

[emaste]

Summary

And drop stray 'd' from the end of some numbers.

[emaste]

tests/sys/cddl/zfs/bin/readmmap.c

86

My guess is this used to be %d and someone made it %ud thinking 'u' is a length modifier not a conversion specifier. Previously this wound print something like short write: 64 != 32d which doesn't make sense.

[kevans]

Hah, whoops