mtd: nand: nandsim: convert to memalloc_noreclaim_*()

mtd: nand: nandsim: convert to memalloc_noreclaim_*()

Nandsim has own functions set_memalloc() and clear_memalloc() for robust
setting and clearing of PF_MEMALLOC.  Replace them by the new generic
helpers.  No functional change.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Vlastimil Babka <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Chris Leech <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Lee Duncan <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Adrian Hunter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>