x86_64: fix non-paravirt compilation

Make sure SWAPGS and PARAVIRT_ADJUST_EXCEPTION_FRAME are properly
defined when CONFIG_PARAVIRT is off.

Fixes Ingo's build failure:
arch/x86/kernel/entry_64.S: Assembler messages:
arch/x86/kernel/entry_64.S:1201: Error: invalid character '_' in mnemonic
arch/x86/kernel/entry_64.S:1205: Error: invalid character '_' in mnemonic
arch/x86/kernel/entry_64.S:1209: Error: invalid character '_' in mnemonic
arch/x86/kernel/entry_64.S:1213: Error: invalid character '_' in mnemonic

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/asm-x86/irqflags.h

@@ -111,7 +111,20 @@ static inline unsigned long __raw_local_irq_save(void)
 #define DISABLE_INTERRUPTS(x)	cli
 
 #ifdef CONFIG_X86_64
+#define SWAPGS	swapgs
+/*
+ * Currently paravirt can't handle swapgs nicely when we
+ * don't have a stack we can rely on (such as a user space
+ * stack).  So we either find a way around these or just fault
+ * and emulate if a guest tries to call swapgs directly.
+ *
+ * Either way, this is a good way to document that we don't
+ * have a reliable stack. x86_64 only.
+ */
 #define SWAPGS_UNSAFE_STACK	swapgs
+
+#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
+
 #define INTERRUPT_RETURN	iretq
 #define USERGS_SYSRET64				\
 	swapgs;					\
@@ -177,15 +190,6 @@ static inline void trace_hardirqs_fixup(void)
 #else
 
 #ifdef CONFIG_X86_64
-/*
- * Currently paravirt can't handle swapgs nicely when we
- * don't have a stack we can rely on (such as a user space
- * stack).  So we either find a way around these or just fault
- * and emulate if a guest tries to call swapgs directly.
- *
- * Either way, this is a good way to document that we don't
- * have a reliable stack. x86_64 only.
- */
 #define ARCH_TRACE_IRQS_ON		call trace_hardirqs_on_thunk
 #define ARCH_TRACE_IRQS_OFF		call trace_hardirqs_off_thunk
 #define ARCH_LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk

include/asm-x86/processor.h

@@ -531,9 +531,6 @@ static inline void load_sp0(struct tss_struct *tss,
 }
 
 #define set_iopl_mask native_set_iopl_mask
-#define SWAPGS	swapgs
-
-#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
 #endif /* CONFIG_PARAVIRT */
 
 /*