Revert "Use %zu to print resid (size_t)."

This reverts commit a1e4c795.

Remove keychord driver, replaced in user space by
https://android-review.googlesource.com/c/677629

.

Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 64114943
Change-Id: I1e2430474a857a53091a5a4c39e160f0ba7ecf25