array_chunks: remove Option wrapper from into_remainder's return type

Author: hkBst

library/core/src/iter/adapters/array_chunks.rs

@@ -46,11 +46,11 @@ where
     /// ```
     #[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")]
     #[inline]
-    pub fn into_remainder(mut self) -> Option<array::IntoIter<I::Item, N>> {
-        if self.remainder.is_none() {
-            while let Some(_) = self.next() {}
+    pub fn into_remainder(mut self) -> array::IntoIter<I::Item, N> {
+        while self.remainder.is_none() {
+            let _ = self.next();
         }
-        self.remainder
+        self.remainder.unwrap()
     }
 }