BUG/MINOR: warning: ‘need_resend’ may be used uninitialized

The commit 201c07f68 ("MAJOR/REORG: dns: DNS resolution task and
requester queues") introduces a warning during compilation:

src/dns.c: In function ‘dns_resolve_recv’:
src/dns.c:487:6: warning: ‘need_resend’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (need_resend) {
      ^

This patch initialize the variable and remove the comment about it.
1 file changed