firewire: sbp2: replace some spin_lock_irqsave by spin_lock_irq

Users of card->lock        Calling context
------------------------------------------------------------------------
sbp2_status_write          AR-req handler, tasklet
complete_transaction       AR-resp or AT-req handler, tasklet
sbp2_send_orb              among else scsi host .queuecommand, which may
                           be called in some sort of atomic context
sbp2_cancel_orbs           sbp2_send_management_orb/
                               sbp2_{login,reconnect,remove},
                               worklet or process
                           sbp2_scsi_abort, scsi eh thread
sbp2_allow_block           sbp2_login, worklet
sbp2_conditionally_block   among else complete_command_orb, tasklet
sbp2_conditionally_unblock sbp2_{login,reconnect}, worklet
sbp2_unblock               sbp2_{login,remove}, worklet or process

Drop the IRQ flags saving from sbp2_cancel_orbs,
sbp2_conditionally_unblock, and sbp2_unblock.
It was already omitted in sbp2_allow_block.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>