Instead of reporting all sockets to cURL, only report the one that has
caused curl_multi_do_locked() to be called.  This lets us get rid of the
QLIST_FOREACH_SAFE() list, which was actually wrong: SAFE foreaches are
only safe when the current element is removed in each iteration.  If it
possible for the list to be concurrently modified, we cannot guarantee
that only the current element will be removed.  Therefore, we must not
use QLIST_FOREACH_SAFE() here.

Fixes: ff5ca166
Cc: qemu-stable@nongnu.org
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20190910124136.10565-6-mreitz@redhat.com
Reviewed-by: NMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>