[PATCH] s390: dasd diag inline assembly

Future versions of gcc may remove initialization code for control blocks used
by the diag250 inline assembly due to incompletely specified constraints.
This may lead to erratic behavior.  Fix the diag250 inline assembly
constraints.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
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>