clean it up a bit

src/main.rs

@@ -26,14 +26,12 @@ fn main() {
                 return None;
             }
 
-            let loc = if line[l - 6] == b';' {
+            let loc = match line[l - 6..][..3] {
-                l - 6
+                [b';', _, _] => l - 6,
-            } else if line[l - 5] == b';' {
+                [_, b';', _] => l - 5,
-                l - 5
+                [_, _, b';'] => l - 4,
-            } else if line[l - 4] == b';' {
+
-                l - 4
+                _ => unreachable!(),
-            } else {
-                unreachable!();
             };
 
             let (city, val) = line.split_at(loc);