Fix some warnings

tests/checkout/crlf.c

@@ -278,7 +278,7 @@ void test_checkout_crlf__autocrlf_true_index_size_is_filtered_size(void)
 void test_checkout_crlf__with_ident(void)
 {
 	git_index *index;
-	git_index_entry *entry;
+	const git_index_entry *entry;
 	git_blob *blob;
 	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
 	opts.checkout_strategy = GIT_CHECKOUT_FORCE;

tests/core/filebuf.c

@@ -233,7 +233,7 @@ void test_core_filebuf__hidden_file(void)
 
 void test_core_filebuf__detects_directory(void)
 {
-	git_filebuf file = GIT_FILEBUF_INIT, fail = GIT_FILEBUF_INIT;
+	git_filebuf file = GIT_FILEBUF_INIT;
 
 	cl_must_pass(p_mkdir("foo", 0777));
 	cl_git_fail_with(GIT_EDIRECTORY, git_filebuf_open(&file, "foo", 0, 0666));

tests/diff/notify.c

@@ -235,6 +235,7 @@ static int progress_abort_diff(
 	const char *new_path,
 	void *payload)
 {
+	GIT_UNUSED(diff_so_far);
 	GIT_UNUSED(old_path);
 	GIT_UNUSED(new_path);
 	GIT_UNUSED(payload);

tests/index/racy.c

@@ -305,7 +305,6 @@ void test_index_racy__read_index_clears_uptodate_bit(void)
 {
 	git_index *index, *newindex;
 	const git_index_entry *entry;
-	git_oid id;
 
 	setup_uptodate_files();