scsi: sd_zbc: Update write pointer offset cache

Recent changes changed the completion of SCSI commands from Soft-IRQ
context to IRQ context. This triggers the following warning, when we're
completing writes to zoned block devices that go through the zone append
emulation:

 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc2+ #2
 Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015
 RIP: 0010:__local_bh_disable_ip+0x3f/0x50
 RSP: 0018:ffff8883e1409ba8 EFLAGS: 00010006
 RAX: 0000000080010001 RBX: 0000000000000001 RCX: 0000000000000013
 RDX: ffff888129e4d200 RSI: 0000000000000201 RDI: ffffffff915b9dbd
 RBP: ffff888113e9a540 R08: ffff888113e9a540 R09: 00000000000077f0
 R10: 0000000000080000 R11: 0000000000000001 R12: ffff888129e4d200
 R13: 0000000000001000 R14: 00000000000077f0 R15: ffff888129e4d218
 FS:  0000000000000000(0000) GS:ffff8883e1400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f2f8418ebc0 CR3: 000000021202a006 CR4: 00000000001706f0
 Call Trace:
  <IRQ>
  _raw_spin_lock_bh+0x18/0x40
  sd_zbc_complete+0x43d/0x1150
  sd_done+0x631/0x1040
  ? mark_lock+0xe4/0x2fd0
  ? provisioning_mode_store+0x3f0/0x3f0
  scsi_finish_command+0x31b/0x5c0
  _scsih_io_done+0x960/0x29e0 [mpt3sas]
  ? mpt3sas_scsih_scsi_lookup_get+0x1c7/0x340 [mpt3sas]
  ? __lock_acquire+0x166b/0x58b0
  ? _get_st_from_smid+0x4a/0x80 [mpt3sas]
  _base_process_reply_queue+0x23f/0x26e0 [mpt3sas]
  ? lock_is_held_type+0x98/0x110
  ? find_held_lock+0x2c/0x110
  ? mpt3sas_base_sync_reply_irqs+0x360/0x360 [mpt3sas]
  _base_interrupt+0x8d/0xd0 [mpt3sas]
  ? rcu_read_lock_sched_held+0x3f/0x70
  __handle_irq_event_percpu+0x24d/0x600
  handle_irq_event+0xef/0x240
  ? handle_irq_event_percpu+0x110/0x110
  handle_edge_irq+0x1f6/0xb60
  __common_interrupt+0x75/0x160
  common_interrupt+0x7b/0xa0
  </IRQ>
  asm_common_interrupt+0x1e/0x40

Don't use spin_lock_bh() to protect the update of the write pointer offset
cache, but use spin_lock_irqsave() for it.

Link: https://lore.kernel.org/r/3cfebe48d09db73041b7849be71ffbcec7ee40b3.1615369586.git.johannes.thumshirn@wdc.com
Fixes: 664f0dce

 ("scsi: mpt3sas: Add support for shared host tagset for CPU hotplug")
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>