crtools: make pid parameter optional for open_image_ro()

Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/crtools.h

@@ -106,7 +106,7 @@ extern void close_image_dir(void);
 
 int open_image(int type, unsigned long flags, ...);
 #define open_image_ro(type, ...) open_image(type, O_RDONLY, ##__VA_ARGS__)
-extern int open_image_ro_nocheck(const char *fmt, int pid);
+extern int open_image_ro_nocheck(const char *fmt, ...);
 
 #define LAST_PID_PATH		"/proc/sys/kernel/ns_last_pid"
 #define LAST_PID_PERM		0666

util.c

@@ -129,15 +129,19 @@ int move_img_fd(int *img_fd, int want_fd)
 	return 0;
 }
 
-int open_image_ro_nocheck(const char *fmt, int pid)
+int open_image_ro_nocheck(const char *fmt, ...)
 {
 	char path[PATH_MAX];
+	va_list args;
 	int tmp;
 
-	sprintf(path, fmt, pid);
+	va_start(args, fmt);
+	vsprintf(path, fmt, args);
+	va_end(args);
+
 	tmp = openat(image_dir_fd, path, O_RDONLY);
 	if (tmp < 0)
-		pr_warn("Can't open image %s for %d: %m\n", fmt, pid);
+		pr_warn("Can't open image %s: %m\n", path);
 
 	return tmp;
 }