UBI: Fastmap updates (v7+)

[Richard Weinberger]

These patches apply on Artems fastmap tree.
git://git.infradead.org/linux-ubi.git#fastmap

[PATCH 01/23] UBI: Fastmap: Fix EC overflow calculation
[PATCH 02/23] UBI: Fastmap: Introduce fm_mutex
[PATCH 03/23] UBI: Fastmap: Fix find_fastmap() logic.
[PATCH 04/23] UBI: Fastmap: Write a fastmap also at detaching
[PATCH 05/23] UBI: Fastmap: Fix memory corruption
[PATCH 06/23] UBI: Fastmap: Serialize ubi_wl_get_peb()
[PATCH 07/23] UBI: Fastmap: Simplify ubi_wl_put_fm_peb() logic
[PATCH 08/23] UBI: Fastmap: make ubi_is_fm_block() static
[PATCH 09/23] UBI: Fastmap: Remove ubi->old_fm logic
[PATCH 10/23] UBI: Fastmap: Allocate and free ubi_attach_info in
[PATCH 11/23] UBI: Fastmap: Fix messages
[PATCH 12/23] ubi: fastmap: harmonize medium erase-counter seek
[PATCH 13/23] UBI: Fastmap: Add comments to fastmap paremters
[PATCH 14/23] UBI: Fastmap: Rename fastmap attributes
[PATCH 15/23] UBI: Fastmap: Use reserved_pebs
[PATCH 16/23] UBI: Fastmap: Store bad_peb_count in fastmap
[PATCH 17/23] UBI: Fastmap: Add ubi_assert()
[PATCH 18/23] UBI: Fastmap: Handle bitflipps correctly
[PATCH 19/23] UBI: Fastmap: Handle protection queue correctly
[PATCH 20/23] UBI: Fastmap: Write fastmap only at detach time if
[PATCH 21/23] UBI: Fastmap: Fix error message
[PATCH 22/23] UBI: Fastmap: Address one of Artems TODOs
[PATCH 23/23] UBI: Fastmap: Make checkpatch.pl happy (again)

All patches have been tested with ubi-tests.

TODO:
- Add a function to UBI which produces a free PEB to be used as
  fastmap super block.

Thanks,
//richard