Fastmap update v2 (pile 3)

[Richard Weinberger]

Artem,

this is pile 3 of 7.

[PATCH 1/6] UBI: Remove alloc_ai() slab name from parameter list
[PATCH 2/6] UBI: Fastmap: Fix race in ubi_eba_atomic_leb_change()
[PATCH 3/6] UBI: Fastmap: Remove bogus ubi_assert()
[PATCH 4/6] UBI: Fastmap: Remove eba_orphans logic
[PATCH 5/6] UBI: Fastmap: Switch to ro mode if invalidate_fastmap()
[PATCH 6/6] UBI: Fastmap: Make WL pool size 50% of user pool size

Thanks,
//richard