fix copy-paste typo in docs for ptr::read_volatile

src/libcore/ptr.rs

@@ -837,7 +837,7 @@ pub unsafe fn write_unaligned<T>(dst: *mut T, src: T) {
 ///
 /// * `src` must be properly aligned.
 ///
-/// Like [`read`], `read_unaligned` creates a bitwise copy of `T`, regardless of
+/// Like [`read`], `read_volatile` creates a bitwise copy of `T`, regardless of
 /// whether `T` is [`Copy`]. If `T` is not [`Copy`], using both the returned
 /// value and the value at `*src` can [violate memory safety][read-ownership].
 /// However, storing non-[`Copy`] types in volatile memory is almost certainly