credential-cache--daemon: use tempfile module

Use the tempfile module to ensure that the socket file gets deleted on
program exit.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

credential-cache--daemon.c

 #include "cache.h"
+#include "tempfile.h"
 #include "credential.h"
 #include "unix-socket.h"
 #include "sigchain.h"
 #include "parse-options.h"
 
-static const char *socket_path;
-
-static void cleanup_socket(void)
-{
-	if (socket_path)
-		unlink(socket_path);
-}
-
-static void cleanup_socket_on_signal(int sig)
-{
-	cleanup_socket();
-	sigchain_pop(sig);
-	raise(sig);
-}
+static struct tempfile socket_file;
 
 struct credential_cache_entry {
 	struct credential item;
@@ -256,6 +244,7 @@ static void check_socket_directory(const char *path)
 
 int main(int argc, const char **argv)
 {
+	const char *socket_path;
 	static const char *usage[] = {
 		"git-credential-cache--daemon [opts] <socket_path>",
 		NULL
@@ -272,14 +261,11 @@ int main(int argc, const char **argv)
 
 	if (!socket_path)
 		usage_with_options(usage, options);
-	check_socket_directory(socket_path);
-
-	atexit(cleanup_socket);
-	sigchain_push_common(cleanup_socket_on_signal);
 
+	check_socket_directory(socket_path);
+	register_tempfile(&socket_file, socket_path);
 	serve_cache(socket_path, debug);
-
-	unlink(socket_path);
+	delete_tempfile(&socket_file);
 
 	return 0;
 }