mm/swapops: rework swap entry manipulation code

mm/swapops: rework swap entry manipulation code

Both migration and device private pages use special swap entries that are
manipluated by a range of inline functions.  The arguments to these are
somewhat inconsistent so rework them to remove flag type arguments and to
make the arguments similar for both read and write entry creation.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alistair Popple <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Ralph Campbell <[email protected]>
Cc: Ben Skeggs <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: "Matthew Wilcox (Oracle)" <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>