Fix lint errors

models/helper.go

@@ -6,7 +6,7 @@ package models
 
 func keysInt64(m map[int64]struct{}) []int64 {
 	var keys = make([]int64, 0, len(m))
-	for k, _ := range m {
+	for k := range m {
 		keys = append(keys, k)
 	}
 	return keys

models/repo.go

@@ -1800,7 +1800,7 @@ type SearchRepoOptions struct {
 func SearchRepositoryByName(opts *SearchRepoOptions) (repos RepositoryList, _ int64, _ error) {
 	var (
 		sess *xorm.Session
-		cond builder.Cond = builder.NewCond()
+		cond = builder.NewCond()
 	)
 
 	if len(opts.Keyword) == 0 {