docs: fix syntax format (vuejs#1452)

Author: Kian-404

src/guide/essentials/computed.md

@@ -213,7 +213,7 @@ export default {
       // setter
       set(newValue) {
         // Note: we are using destructuring assignment syntax here.
-        ;[this.firstName, this.lastName] = newValue.split(' ')
+        [this.firstName, this.lastName] = newValue.split(' ')
       }
     }
   }
@@ -241,7 +241,7 @@ const fullName = computed({
   // setter
   set(newValue) {
     // Note: we are using destructuring assignment syntax here.
-    ;[firstName.value, lastName.value] = newValue.split(' ')
+    [firstName.value, lastName.value] = newValue.split(' ')
   }
 })
 </script>