fix warnings in async render code.. and well.. warn about it - it

fix warnings in async render code.. and well.. warn about it - it
crashes for me in expedite with 4 cores on x86 at random points. looks
like it's bitrotting. though it was relatively tentative to begin with.

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/evas@53856 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33