tests/vhost-user-bridge.c: fix fd leakage This fixes file descriptor leakage in vhost-user-bridge application. Whenever a new callfd or kickfd is set, the previous one should be explicitly closed. File descriptors used to map guest's memory are closed immediately after mmap call. Signed-off-by: Victor Kaplansky <victork@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>