chore: fix comment typo

Author: Magiccwl

src/core/instance/render.js

@@ -84,7 +84,7 @@ export function renderMixin (Vue: Class<Component>) {
     // render self
     let vnode
     try {
-      // There's no need to maintain a stack becaues all render fns are called
+      // There's no need to maintain a stack because all render fns are called
       // separately from one another. Nested component's render fns are called
       // when parent component is patched.
       currentRenderingInstance = vm