pvmove: fix pvmove --abort or pvmove w/o parameters

pvmove: fix pvmove --abort or pvmove w/o parameters

_check_lv_status was called from within dm_list_iterate_items cycle.
This was utterly wrong! _check_lv_status may remove more than one LV from
vg->lvs list we iterated in the same time.

In some scenarios this could lead to deadlock iterationg over same LV
indefinitely or segfault depending on the circumstances.

Fixed by moving the _check_lv_status outside iterating the vg->lvs
list.

Note that commit 6e7b24d34ff3da1c56718bb7def8a8ecd4258c43 was not enough
as _check_lv_status may result in removal of more than one LV from the list.