mm/nommu: use file_has_valid_mmap_hooks() helper

mm/nommu: use file_has_valid_mmap_hooks() helper

Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file
callback"), the f_op->mmap() hook has been deprecated in favour of
f_op->mmap_prepare().

Therefore, update the check for file operations supporting mmap() by using
the file_has_valid_mmap_hooks() helper function, which checks for either
f_op->mmap or f_op->mmap_prepare rather than checking only for f_op->mmap
directly.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/5f120b644b5890d1b50202d0f0d4c9f0d6b62873.1750099179.git.lorenzo.stoakes@oracle.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>