p.haul: minor fixups for pre_dump variable of phaul_iter_worker
p.haul: minor fixups for pre_dump variable of phaul_iter_worker

Remove redundant multiple initialization for pre_dump variable and
rename it to __pre_dump to make it private.

Signed-off-by: Nikita Spiridonov <e2c2785991de10f66b050593578d4296c6c8705d@odin.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

arthurlockman/p.haul,aburluka/p.haul,xemul/p.haul,jne100/p.haul,xemul/p.haul,xemul/p.haul,arthurlockman/p.haul,jne100/p.haul,arthurlockman/p.haul,arthurlockman/p.haul,arthurlockman/p.haul,jne100/p.haul,xemul/p.haul,aburluka/p.haul,aburluka/p.haul,jne100/p.haul,aburluka/p.haul,aburluka/p.haul,jne100/p.haul,xemul/p.haul