Make is_partial_io()/valid_io_request()/page_zero_filled() return boolean,
since each function only uses either one or zero as its return value.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>