docs: fix rustdoc::bare_urls

Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>

Author: mkroening

src/structures/paging/mapper/recursive_page_table.rs

@@ -54,7 +54,7 @@ impl<'a> RecursivePageTable<'a> {
     /// because allocating the last byte of the address space can lead to pointer
     /// overflows and undefined behavior. For more details, see the discussions
     /// [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/136281-t-opsem/topic/end-of-address-space)
-    /// and [in the `unsafe-code-guidelines ` repo]https://github.com/rust-lang/unsafe-code-guidelines/issues/420).
+    /// and [in the `unsafe-code-guidelines ` repo](https://github.com/rust-lang/unsafe-code-guidelines/issues/420).
     #[inline]
     pub fn new(table: &'a mut PageTable) -> Result<Self, InvalidPageTable> {
         let page = Page::containing_address(VirtAddr::new(table as *const _ as u64));