cli: wire shelve flag; more clippy fixes

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I694da71afe93bcb33687ff7d8e75f04f6a6a6964

src/cli/commands/fork.rs

@@ -211,13 +211,12 @@ fn execute_init(
           .args(["log", "--limit", "1", "--template", ""])
           .current_dir(path)
           .output()
+          && !output.stdout.is_empty()
         {
-          if !output.stdout.is_empty() {
-            println!(
-              "Note: Jujutsu repository detected. Make sure to run 'jj git \
-               push' to sync changes with remote if needed."
-            );
-          }
+          println!(
+            "Note: Jujutsu repository detected. Make sure to run 'jj git \
+             push' to sync changes with remote if needed."
+          );
         }
       },
       VcsType::None => {