x86, cmpxchg: Move 64-bit set64_bit() to match 32-bit

Reduce arbitrary differences between 32 and 64 bits.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Link: http://lkml.kernel.org/r/4E5BCC40.3030501@goop.orgSigned-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/cmpxchg_64.h

@@ -3,11 +3,6 @@
 
 #include <asm/alternative.h> /* Provides LOCK_PREFIX */
 
-static inline void set_64bit(volatile u64 *ptr, u64 val)
-{
-	*ptr = val;
-}
-
 extern void __xchg_wrong_size(void);
 extern void __cmpxchg_wrong_size(void);
 
@@ -66,6 +61,11 @@ extern void __cmpxchg_wrong_size(void);
 #define xchg(ptr, v)							\
 	__xchg((v), (ptr), sizeof(*ptr))
 
+static inline void set_64bit(volatile u64 *ptr, u64 val)
+{
+	*ptr = val;
+}
+
 #define __HAVE_ARCH_CMPXCHG 1
 
 /*