s390/qdio: roll-back after queue allocation error

When qdio_allocate_qs() fails, have it deal with its previous
allocations.
This way qdio_allocate() doesn't need to clean up afterwards.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>