ext4: clear the dirty bit for a page in writeback at the last minute

Move when we call clear_page_dirty_for_io() to just before we actually
write the page.  This simplifies the code somewhat, and avoids marking
pages as clean and then needing to remark them as dirty later.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --cc fs/ext4/inode.c
Simple merge