compositor.c: Prepare output information in create
compositor.c: Prepare output information in create

Makes things such as wlc_output_get_name work in output.created
@SirCmpwn

ss1h2a3tw/wlc,Earnestly/wlc,gpyh/wlc,lkundrak/wlc,lkundrak/wlc,ammen99/wlc,vially/wlc,scarabeusiv/wlc,Cloudef/wlc,Enerccio/ewlc,Enerccio/ewlc,ammen99/wlc,yohanesu75/wlc,scarabeusiv/wlc,vially/wlc,Cloudef/wlc,yohanesu75/wlc,gpyh/wlc,ss1h2a3tw/wlc,Earnestly/wlc