khash fails make check under OTP-20

[wohali]

Expected Behaviour

make check should pass.

Current Behaviour

  khash iterators no exipiration functions
    khash_test:219: no_expiration_iterators_test_ (to_list doesn't expire iterat
ors)...ok
    khash_test:226: no_expiration_iterators_test_ (lookup doesn't expire iterato
rs)...ok
    khash_test:233: no_expiration_iterators_test_ (get doesn't expire iterators)
...ok
    khash_test:240: no_expiration_iterators_test_ (size doesn't expire iterators
)...ok
    undefined
    *** instantiation of subtests failed ***
**in function khash_test:'-no_expiration_iterators_test_/0-fun-14-'/1 (test/khas
h_test.erl, line 244)
**error:{badmatch,{ok,#Ref<0.2024853654.2929852417.103552>}}

[wohali]

This is a child ticket of #617

[nickva]

Fixed