erofs: simplify iloc()

erofs: simplify iloc()

[ Upstream commit b780d3fc6107464dcc43631a6208c43b6421f1e6 ]

Actually we could pass in inodes directly to clean up all callers.
Also rename iloc() as erofs_iloc().

Link: https://lore.kernel.org/r/20230114150823.432069-1-xiang@kernel.org
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Stable-dep-of: 001b8ccd0650 ("erofs: fix compact 4B support for 16k block size")
Signed-off-by: Sasha Levin <sashal@kernel.org>