x86/compat: Check for both 32-bit compat and x32 in get_gate_vma()

Change this to CONFIG_COMPAT so both 32-bit compat and x32 will
do the check.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1434974121-32575-8-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/entry/vsyscall/vsyscall_64.c

@@ -290,7 +290,7 @@ static struct vm_area_struct gate_vma = {
 
 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 {
-#ifdef CONFIG_IA32_EMULATION
+#ifdef CONFIG_COMPAT
 	if (!mm || mm->context.ia32_compat)
 		return NULL;
 #endif