refactor(cli/self-update)!: reorganize InstallOpts methods

src/cli/common.rs

@@ -173,7 +173,7 @@ fn show_channel_updates(
                 // this is a bit strange: we don't supply the version we
                 // presumably had (for Installed and Unchanged), so we query it
                 // again. Perhaps we can do better.
-                let version = match Toolchain::new(cfg, name.into()) {
+                let version = match Toolchain::new(cfg, name.clone().into()) {
                     Ok(t) => t.rustc_version(),
                     Err(_) => String::from("(toolchain not installed)"),
                 };

src/cli/rustup_mode.rs

@@ -873,7 +873,7 @@ async fn default_(
                 cfg.set_default(None)?;
             }
             MaybeResolvableToolchainName::Some(ResolvableToolchainName::Custom(toolchain_name)) => {
-                Toolchain::new(cfg, (&toolchain_name).into())?;
+                Toolchain::new(cfg, toolchain_name.clone().into())?;
                 cfg.set_default(Some(&toolchain_name.into()))?;
             }
             MaybeResolvableToolchainName::Some(ResolvableToolchainName::Official(toolchain)) => {