Fastmap update v2 (pile 6)

[Richard Weinberger]

Artem,

this is pile 6 of 7.

[PATCH 1/6] UBI: Move fastmap specific functions out of wl.c
[PATCH 2/6] UBI: Add accessor functions for WL data structures
[PATCH 3/6] UBI: Fastmap: Wire up WL accessor functions
[PATCH 4/6] UBI: Fastmap: Introduce ubi_fastmap_init()
[PATCH 5/6] UBI: Fastmap: Introduce may_reserve_for_fm()
[PATCH 6/6] UBI: Fastmap: Remove else after return.

Thanks,
//richard