Fix a couple of warnings

src/repository.c

@@ -1264,7 +1264,7 @@ int git_repository_head_orphan(git_repository *repo)
 	return 0;
 }
 
-int at_least_one_cb(const char *refname, void *payload)
+static int at_least_one_cb(const char *refname, void *payload)
 {
 	GIT_UNUSED(refname);
 	GIT_UNUSED(payload);
@@ -1287,7 +1287,7 @@ static int repo_contains_no_reference(git_repository *repo)
 int git_repository_is_empty(git_repository *repo)
 {
 	git_reference *head = NULL;
-	int error, ref_count = 0;
+	int error;
 
 	if (git_reference_lookup(&head, repo, GIT_HEAD_FILE) < 0)
 		return -1;

src/revparse.c

@@ -268,7 +268,7 @@ static int retrieve_oid_from_reflog(git_oid *oid, git_reference *ref, unsigned i
 		goto cleanup;
 
 	} else {
-		int i;
+		unsigned int i;
 		git_time commit_time;
 
 		for (i = 0; i < numentries; i++) {

tests-clar/config/read.c

@@ -446,7 +446,6 @@ void test_config_read__can_load_and_parse_an_empty_config_file(void)
 void test_config_read__cannot_load_a_non_existing_config_file(void)
 {
 	git_config *cfg;
-	int i;
 
 	cl_assert_equal_i(GIT_ENOTFOUND, git_config_open_ondisk(&cfg, "./no.config"));
 }