Nobody checks this flag on ext4 folios, stop setting and clearing it.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240420025029.2166544-11-willy@infradead.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>