tiny imsg_init(3) correction in EXAMPLES

[Anton Maksimenkov]

Hi.

I found that manpage for imsg-family have a little mistake:
...
                   if (msgbuf_write(ibuf->w) < 0) {
...

It seems it should be:
                   if (msgbuf_write(&ibuf->w) < 0) {
-- 
antonvm