Simplify CheckUnitUser logic (#12854)

if check one user's unit in different repos, it's not necessary to
get user data every time.

Signed-off-by: a1012112796 <1012112796@qq.com>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

routers/home.go

@@ -303,10 +303,8 @@ func ExploreCode(ctx *context.Context) {
 		repoIDs []int64
 		err     error
 		isAdmin bool
-		userID  int64
 	)
 	if ctx.User != nil {
-		userID = ctx.User.ID
 		isAdmin = ctx.User.IsAdmin
 	}
 
@@ -336,7 +334,7 @@ func ExploreCode(ctx *context.Context) {
 		var rightRepoMap = make(map[int64]*models.Repository, len(repoMaps))
 		repoIDs = make([]int64, 0, len(repoMaps))
 		for id, repo := range repoMaps {
-			if repo.CheckUnitUser(userID, isAdmin, models.UnitTypeCode) {
+			if repo.CheckUnitUser(ctx.User, models.UnitTypeCode) {
 				rightRepoMap[id] = repo
 				repoIDs = append(repoIDs, id)
 			}