asm-generic: Fix 32 bit __generic_cmpxchg_local

Commit 656e9007 ("asm-generic: avoid __generic_cmpxchg_local
warnings") introduced a typo that means the code is incorrect for 32 bit
values. It will work fine for postive numbers, but will fail for
negative numbers on a system where longs are 64 bit.

Fixes: 656e9007 ("asm-generic: avoid __generic_cmpxchg_local warnings")
Signed-off-by: David McKay <david.mckay@codasip.com>
Signed-off-by: Stuart Menefy <stuart.menefy@codasip.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

include/asm-generic/cmpxchg-local.h

@@ -34,7 +34,7 @@ static inline unsigned long __generic_cmpxchg_local(volatile void *ptr,
 			*(u16 *)ptr = (new & 0xffffu);
 		break;
 	case 4: prev = *(u32 *)ptr;
-		if (prev == (old & 0xffffffffffu))
+		if (prev == (old & 0xffffffffu))
 			*(u32 *)ptr = (new & 0xffffffffu);
 		break;
 	case 8: prev = *(u64 *)ptr;