[Sheepdog] [PATCH v2 0/2] optimization to oid_to_vnode and obj_to_sheep

[levin li]

In this version:

1. removed oid_to_vnode.
2. use obj_to_sheeps() to replace obj_to_sheep() in collie/vdi.c
3. remove hval_to_sheep() and hval_to_sheeps().
4. use for loop to replace goto struct.