locking/atomic/x86: Correct the definition of __arch_try_cmpxchg128()

Correct the definition of __arch_try_cmpxchg128(), introduced by:

  b23e139d ("arch: Introduce arch_{,try_}_cmpxchg128{,_local}()")

Fixes: b23e139d ("arch: Introduce arch_{,try_}_cmpxchg128{,_local}()")
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240408091547.90111-2-ubizjak@gmail.com

arch/x86/include/asm/cmpxchg_64.h

@@ -62,7 +62,7 @@ static __always_inline u128 arch_cmpxchg128_local(volatile u128 *ptr, u128 old,
 	asm volatile(_lock "cmpxchg16b %[ptr]"				\
 		     CC_SET(e)						\
 		     : CC_OUT(e) (ret),					\
-		       [ptr] "+m" (*ptr),				\
+		       [ptr] "+m" (*(_ptr)),				\
 		       "+a" (o.low), "+d" (o.high)			\
 		     : "b" (n.low), "c" (n.high)			\
 		     : "memory");					\