[SCSI] ibmvscsi: Fix slave_configure deadlock

No locks should be held when calling scsi_adjust_queue_depth
so drop the lock in slave_configure prior to calling it.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>