Merge loop.h into loop.c as all the content is only used there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220419063303.583106-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>