mm/filemap: avoid type conversion

The return type of function folio_test_hugetlb is bool type, there is no
need to assign it to an integer type.

Link: https://lkml.kernel.org/r/20240108044815.3291487-1-lihongbo22@huawei.com


Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>