rename member name of struct gaicb in netdb.h

libbsd define __unused as __attribute__((__unused__)) which conflicts with the name of this struct. The upstream glibc changes the member name to __glibc_reserved. This patch
uses the same name from upstream.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4207
[email protected]

Review URL: https://codereview.chromium.org/1214183004.
1 file changed