x86/vsyscall_emu/64: Don't use RET in vsyscall emulation

This is userspace code and doesn't play by the normal kernel rules.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: NBorislav Petkov <bp@suse.de>

arch/x86/entry/vsyscall/vsyscall_emu_64.S

@@ -19,17 +19,20 @@ __vsyscall_page:
 
 	mov $__NR_gettimeofday, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_time, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_getcpu, %rax
 	syscall
-	RET
+	ret
+	int3
 
 	.balign 4096, 0xcc