Fix style issues coming from recent merge

I apparently merged the 'inflection' branch without checking the code
style. This means that a lot of warnings are being raised by clippy and
I'm unsure which commit did what. Since I'm lazy about this right now,
let's bring all fixes in a single commit.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/crates/cli/src/exercises.rs b/crates/cli/src/exercises.rs
index b153aca..518f604 100644
--- a/crates/cli/src/exercises.rs
+++ b/crates/cli/src/exercises.rs
@@ -4,8 +4,8 @@ use std::vec::IntoIter;
 
 // Show the help message.
 fn help(msg: Option<&str>) {
-    if msg.is_some() {
-        println!("{}.\n", msg.unwrap());
+    if let Some(msg) = msg {
+        println!("{}.\n", msg);
     }
 
     println!("mihi exercises: Manage exercises.\n");