needs_to_be_kept_alive() incorrectly calculates it's return value

With the fix in a3023bae the new inline function needs_to_be_kept_alive(igloo_ro_stub_t) was added to the ro-subsystem. It took the old check for the reference counter. However the counter is now updated before the function is called (before it was updated later). Hence the check is no longer valid (off by one).

This will result in needs_to_be_kept_alive(igloo_ro_stub_t) to return false (and hence lead to freeing of the object) too early. This in turns allows for valid code to end up in a use-after-free situation.