BACKPORT: erofs: simplify iloc()

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

Bug: 303691233

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>
(cherry picked from commit b780d3fc)
[dhavale: resolved minor conflict in fs/erofs/zmap.c]
Signed-off-by: Sandeep Dhavale <dhavale@google.com>

Change-Id: Iea7a97040cebdc984e2956d421755230263c97ae