x86_64: make atomic64_t work like atomic_t

Regardless of the greater controversy about the semantics of atomic_t, I think we can all agree that atomic_t and atomic64_t should have the same semantics. This is presently not the case on x86_64, where the volatile keyword was removed from the declaration of atomic_t, but it was not removed from the declaration of atomic64_t. The following patch fixes that inconsistency, without delving into anything more controversial.

From: Chris Snook <[email protected]>

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.

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