x86: make atomic64_t work like atomic_t

The volatile keyword has already been removed from the declaration of atomic_t
on x86_64.  For consistency, remove it from atomic64_t as well.

[ tglx: arch/x86 adaptation ]
Signed-off-by: Chris Snook <csnook@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/atomic_64.h

@@ -206,7 +206,7 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v)
 
 /* An 64bit atomic type */
 
-typedef struct { volatile long counter; } atomic64_t;
+typedef struct { long counter; } atomic64_t;
 
 #define ATOMIC64_INIT(i)	{ (i) }