(4/5) Remove unused parameters from allocate_extents()

This patch removes unused 'status' parameter from allocate_extents().

Guessing from the lv_extend(), 'status' is related to lv->status. However, allocate_extents() only allocates extents. Mapping extents to LV segment is done in other functions. So the parameter seems no use in future, too.

Thanks,

Jun'ichi Nomura, NEC Corporation of America