vfs: widen inode hash/lookup functions to u64

vfs: widen inode hash/lookup functions to u64

Change the inode hash/lookup VFS API functions to accept u64 parameters
instead of unsigned long for inode numbers and hash values. This is
preparation for widening i_ino itself to u64, which will allow
filesystems to store full 64-bit inode numbers on 32-bit architectures.

Since unsigned long implicitly widens to u64 on all architectures, this
change is backward-compatible with all existing callers.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260304-iino-u64-v3-1-2257ad83d372@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>