Fix incorrect separator for match arms

src/matches.rs

@@ -224,7 +224,7 @@ fn rewrite_match_arms(
             .zip(beginning_verts.into_iter())
             .map(|((arm, is_last), beginning_vert)| ArmWrapper::new(arm, is_last, beginning_vert)),
         "}",
-        "|",
+        ",",
         |arm| arm.span().lo(),
         |arm| arm.span().hi(),
         |arm| arm.rewrite_result(context, arm_shape),

tests/source/issue-6373.rs

@@ -0,0 +1,8 @@
+fn main() {
+    let x: Option<i32> = Some(10);
+    let value = match x {
+        Some(i) => i /* comment */,
+        None => 0,
+    };
+    println!("{}", value);
+}

tests/target/issue-6373.rs

@@ -0,0 +1,8 @@
+fn main() {
+    let x: Option<i32> = Some(10);
+    let value = match x {
+        Some(i) => i, /* comment */
+        None => 0,
+    };
+    println!("{}", value);
+}