libevdev: move input event logging very close to read().

We want to be sure we aren't missing any input events, even if they
come in with odd timestamps.

BUG=chromium-os:33601
TEST=tested on device; dumped log looked correct

Change-Id: I9c6e99b7bed6580b84f50cfa80766a8eb08489d4
Reviewed-on: https://gerrit.chromium.org/gerrit/30637
Commit-Ready: Andrew de los Reyes <adlr@chromium.org>
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>
Tested-by: Andrew de los Reyes <adlr@chromium.org>