block/partitions/atari: Remove redundant assignment

Get rid of redundant assignment to a variable part_fmt from function
atari_partition. It is being assigned a value that is never read until
the end of function.

Reported by clang-tidy [deadcode.DeadStores]

Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com>
Link: https://lore.kernel.org/r/20220423113811.13335-4-michalorzel.eng@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>