wireup linux/name_to_handle_at and name_to_handle_at syscalls

src/linux/name_to_handle_at.c

@@ -0,0 +1,10 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include "syscall.h"
+
+int name_to_handle_at(int dirfd, const char *pathname,
+	struct file_handle *handle, int *mount_id, int flags)
+{
+	return syscall(SYS_name_to_handle_at, dirfd,
+		pathname, handle, mount_id, flags);
+}

src/linux/open_by_handle_at.c

@@ -0,0 +1,8 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include "syscall.h"
+
+int open_by_handle_at(int mount_fd, struct file_handle *handle, int flags)
+{
+	return syscall(SYS_open_by_handle_at, mount_fd, handle, flags);
+}