Use automatic links in generated docs

Fix several rustdoc bare URL warnings in the generated documentation.

See-also: https://doc.rust-lang.org/rustdoc/lints.html#bare_urls
Signed-off-by: Carlos López <carlos.lopez@suse.com>

Author: 00xc

src/cmdline/mod.rs

@@ -324,7 +324,7 @@ impl Cmdline {
 
     /// Returns a C compatible representation of the command line
     /// The Linux kernel expects a null terminated cmdline according to the source:
-    /// https://elixir.bootlin.com/linux/v5.10.139/source/kernel/params.c#L179
+    /// <https://elixir.bootlin.com/linux/v5.10.139/source/kernel/params.c#L179>
     ///
     /// To get bytes of the cmdline to be written in guest's memory (including the
     /// null terminator) from this representation, use CString::as_bytes_with_nul()

src/loader/mod.rs

@@ -147,12 +147,12 @@ pub struct KernelLoaderResult {
     /// blob and initrd will be loaded adjacent to kernel image.
     pub kernel_end: GuestUsize,
     /// Configuration for the VMM to use to fill zero page for bzImage direct boot.
-    /// See https://www.kernel.org/doc/Documentation/x86/boot.txt.
+    /// See <https://www.kernel.org/doc/Documentation/x86/boot.txt>.
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
     pub setup_header: Option<bootparam::setup_header>,
     /// Availability of a PVH entry point. Only used for ELF boot, indicates whether the kernel
     /// supports the PVH boot protocol as described in:
-    /// https://xenbits.xen.org/docs/unstable/misc/pvh.html
+    /// <https://xenbits.xen.org/docs/unstable/misc/pvh.html>
     #[cfg(all(feature = "elf", any(target_arch = "x86", target_arch = "x86_64")))]
     pub pvh_boot_cap: elf::PvhBootCapability,
 }