[Shootout-list] Fixed version of OCaml sumcol benchmark

[Yaron Minsky]

The OCaml sumcol benchmark assumes stdin, which appears to be wrong. 
Here's a fixed version:

let sum = ref 0
let inchan = open_in Sys.argv.(1)
let rec loop () = sum := !sum + int_of_string (input_line inchan); loop ();;
try loop () with End_of_file -> Printf.printf "%d\n" !sum