lwt.ml: whitespace: break up some long lines
lwt.ml: whitespace: break up some long lines

The preceding commits made some lines in lwt.ml really long; this commit
breaks them up.

ocsigen/lwt,ocsigen/lwt,c-cube/lwt,ocsigen/lwt,rneswold/lwt,rneswold/lwt,c-cube/lwt,c-cube/lwt,rneswold/lwt