make the print functions into actual functions lol

src/day1.ml

@@ -23,7 +23,7 @@ let part2 lines =
   | _ -> failwith "wtf"
 ;;
 
-let print =
+let print () =
   let lines = Utils.lines_of_file "inputs/day1.tt" in
   Printf.(
     printf "Day 1.1: %d\n" @@ part1 lines;

src/day2.ml

@@ -86,7 +86,7 @@ let part2 lines =
     lines
 ;;
 
-let print =
+let print () =
   let lines = Utils.lines_of_file "./inputs/day2.tt" in
   Printf.(
     printf "Day 2.1: %d\n" @@ part1 lines;