tmem: remove unneeded parameters from obj destroy path

tmem: remove unneeded parameters from obj destroy path

Parameters "selective" and "no_rebalance" are meaningless in obj
destroy path, this patch remove them. No place uses
no_rebalance=1. In the obj_destroy path we always call it with
no_balance=0.

Note that this will now free it only if:

   obj->last_client == cli_id

Which is OK - even if we allocate a non-shared pool we set by
default the obj->last_client to TMEM_CLI_ID_NULL so even if
the pool is never used, the pool_flush will take care of removing
those.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>