Replace the need for taskCHECK_READY_LIST() by instead making vListRemove() return...

Replace the need for taskCHECK_READY_LIST() by instead making vListRemove() return the number of items that remain in the list once the list item has been removed.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@1784 1d2547de-c912-0410-9cb9-b8ca96c0e9e2