mm: add writeback.h to docs build

There's four functions in this header file with kernel-doc; add them to
the htmldocs.

Link: https://lore.kernel.org/20260615162244.2170866-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2026-06-15 17:22:41 +01:00 • committed by Andrew Morton
commit eafe0dcdc0