* fhandler.cc (fhandler_base::fstat): Move dev and ino calculation into caller.

* fhandler.cc (fhandler_base::fstat): Move dev and ino calculation into caller.
* syscalls.cc (stat_worker): Calculate dev and ino calculation here, if zero.
* fhandler_proc.cc (fhandler_proc::fhandler_proc): Minor reorg for debugging.
* fhandler_process.cc (fhandler_process::exists): Return 0 on nonexistence.
(fhandler_process::fstat): Simplify pid logic.
* fhandler_tape.cc (fhandler_dev_tape::fstat): Minor reformatting.