What - refine mkdir of kpfs, we will return after find the parent_node, otherwise, it will enter p==parent_path.
What - refine mkdir of kpfs, we will return after find the parent_node,
otherwise, it will enter p==parent_path.

@Description/root cause - Why
1. we should return when find parent_node.
2. kuaipan API could let user to create deep children path directly, so we need to
find the available path in node. but in mkdir -p, it will create sub dir one
by one.

@Resolution - How
1. change do while to while(1)
2. return when find parent_node

@Reviewer
None

@Tickets
NONE

mimepp/kpfs,mimepp/kpfs