lib ldb key value: Remove check_parent from ldb_kv_index_idxptr()

lib ldb key value: Remove check_parent from ldb_kv_index_idxptr()

The callers will soon have two possible parents for this pointer, so
we need to remove this check, which was added out of caution given
the rather strange pattern of putting an active memory pointer into a
TDB (as a hash map).

That is, the only callers that did call this with "true" would
have to call this with "false", so just remove the complexity.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>