mm/page-flags: make PageUptodate return bool

Make PageUptodate return bool to align the return values of
folio_test_uptodate function

Link: https://lkml.kernel.org/r/20240422032725.41452-1-gehao@kylinos.cn


Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ruihan Li <lrh2000@pku.edu.cn>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>