And remove the bogus check for a NULL return value from kmap, which
can't happen.  While we're at it: I don't think that kmapping up to 256
will work without deadlocks on highmem machines, a better idea would
be to use vm_map_ram to map all of them into a single virtual address
range.  Incidentally that would also simplify the code a lot.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>