refactor parse_pending_delete to sane implemenation

refactor parse_pending_delete to sane implemenation

this was quite the mess, a perl greedy match over non-whitespace
character is equivalent to a split on whitespace on, but the latter
is much easier to grasp when looking at this the first time.

Do a real for loop with real variable names and less nest everything
into one line.

the test added in the previous commit should give use the safety net
for that cleanup.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>