Resolve warnings on iOS with no-default-features and disk

`cargo check --target=aarch64-apple-ios --no-default-features --features=disk`

    warning: unused import: `self::ios as inner`
      --> src/unix/apple/mod.rs:15:24
       |
    15 |         pub(crate) use self::ios as inner;
       |                        ^^^^^^^^^^^^^^^^^^
       |
       = note: `#[warn(unused_imports)]` on by default

src/unix/apple/mod.rs

@@ -10,7 +10,7 @@ cfg_if! {
     if #[cfg(all(target_os = "macos", any(feature = "disk", feature = "system", feature = "component")))] {
         pub(crate) mod macos;
         pub(crate) use self::macos as inner;
-    } else if #[cfg(all(target_os = "ios", any(feature = "disk", feature = "system", feature = "component")))] {
+    } else if #[cfg(all(target_os = "ios", any(feature = "system", feature = "component")))] {
         pub(crate) mod ios;
         pub(crate) use self::ios as inner;
     }