[PATCH] Updated osst driver for 2.6.x

[PATCH] Updated osst driver for 2.6.x

From: Willem Riede <wrlk@riede.org>

Brings 2.6.x version of osst up to par with the 2.4.y version.
Except for the /proc changes
Tested against released 2.6.0 kernel.

Changes from what's in the kernel tree today:

- Fixes bug that files shorter than one 32K frame don't get written.
- Fix a memory alloc/free mismatch that could have made your kernel unstable after rmmod osst.
- Fix a number of tape (re)positioning bugs around filemarks that affected Amanda, Arkeia and
  Storix backup software.
- Rationalize module parameters.
- Fix time-out skipping to EOD
- Write FM+EOD+Header-update when file write terminated by ioctl
- Follow standard Unix behavior for read at EOD (return zero bytes read twice then error)
- Implement SETBLK ioctl (allowed before first write only)