[PATCH] s390: channel tape fixes

Tape driver fixes:
 - Added deferred condition handling to tape driver core.
 - Added ability to handle busy conditions.
 - Code cleanup.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>