Remove redundant into_iter and collect

src/day1.rs

@@ -13,11 +13,11 @@ fn total_fuel(mass: u64) -> u64 {
 
 pub fn main() -> io::Result<()> {
     let f = BufReader::new(File::open("day1-input.txt")?);
-    let masses: Vec<u64> = f
+    let total: u64 = f
         .lines()
         .map(|line| line.unwrap().parse().unwrap())
-        .collect();
-    let total: u64 = masses.into_iter().map(total_fuel).sum();
+        .map(total_fuel)
+        .sum();
     println!("Fuel needed for bringing Santa home is: {}", total);
 
     Ok(())