Add missing syscall wrapper for x32_rt_sigreturn().
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NDominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-6-brgerst@gmail.com