ext4: move ext4_fill_raw_inode() related functions

In preparation for calling ext4_fill_raw_inode() in
__ext4_get_inode_loc(), move three related functions before
__ext4_get_inode_loc(), no logical change.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210901020955.1657340-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>