[FE] refactor: scrollTop에서 ref로 접근하는 방식으로 변경

frontend/src/hooks/common/useScroll.ts

@@ -2,17 +2,18 @@ import type { RefObject } from 'react';
 
 const useScroll = () => {
   const scrollToTop = <T extends HTMLElement>(ref: RefObject<T>) => {
-    if (!ref.current) {
-      return;
+    if (ref.current) {
+      ref.current.scrollTo(0, 0);
     }
-
-    ref.current?.scrollTo(0, 0);
   };
 
   const scrollToPosition = <T extends HTMLElement>(ref: RefObject<T>) => {
-    setTimeout(() => {
-      ref.current?.scrollIntoView({ behavior: 'smooth' });
-    }, 100);
+    if (ref.current) {
+      const timeout = setTimeout(() => {
+        ref.current?.scrollIntoView({ behavior: 'smooth' });
+        clearTimeout(timeout);
+      }, 100);
+    }
   };
 
   return { scrollToTop, scrollToPosition };