refactor: 의미 없는 if문 제거

src/pages/LoginPage/components/SignupModal.jsx

@@ -161,14 +161,12 @@ const SignupModal = ({ onClose }) => {
     }
   
     try {
-      const result = await axiosSignup(formData);
-      if (result) {
+      await axiosSignup(formData);
       const data = await axiosLogin(formData);
       sessionStorage.setItem('accessToken', data.token);
       // 만료 시간도 저장
       sessionStorage.setItem('tokenExpiresAt', data.expiresAt.toString());
       window.location.href = '/';
-      }
     } catch (error) {
       setErrors(prev => ({
         ...prev,