Small memory leak fix in hostip.c

[iCMDdev]

Hi!

First time looking at the curl source code, and I think I found a (most likely insignificant) memory leak.
Either way, I added a free(ca); to prevent memory leaks if Curl_inet_pton(AF_INET6, "::1", ipv6) fails in *get_localhost6(int port, const char *name).

[bagder]

While this is "technically correct", in that if Curl_inet_pton() returns failure this would leak. But given this input, the function will not fail so it will never return anything but 1 for this code flow.

I rather suggest that we instead make the code reflect this reality, perhaps like this:

    (void)Curl_inet_pton(AF_INET6, "::1", ipv6);

[bagder]

See comment

[iCMDdev]

Makes sense! Yeah, that's a better choice.

[bagder]

Thanks!

[iCMDdev]

No problem, thanks for the commit!