fix macro define for freeaddrinfo with asyncns
previously, this define was only made in lm-asyncns-resolver.c, which
does not propagate it to lm-resolver.c, where freeaddrinfo() is used.
this means that when asyncns support is used, the standard libc
freeaddrinfo() is called on an addrinfo acquired from
asyncns_getaddrinfo, which is undefined behaviour, and leads to a
segfault on musl libc.