swim3: fix the floppy_locked_ioctl prototype

Add back the accidentally dropped mode parameter.

Fixes: b60f7635788a ("swim3: fix the floppy_locked_ioctl prototype")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230613154309.327557-1-hch@lst.de


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