MINOR: tree-wide: use free_acl_cond() where relevant

Now that we have free_acl_cond(cond) function that does cond prune then
frees cond, replace all occurences of this pattern:

   | prune_acl_cond(cond)
   | free(cond)

with:

   | free_acl_cond(cond)
7 files changed