[SCSI] lpfc 8.3.12: Critical fixes

- Move the code to increase the sg seg count for LP21000 adapters.
- Check pcmd on command completion before dereferencing it.
- Clear queue memory when creating firmware queues to prevent stale entries.
- Replace the use of PAGE_SIZE in many areas that assumed it was always 4k.
- Add an else clause to a conditional that needed to unlock the hba_lock.

Signed-off-by: Alex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>