atomic: fix a typo in atomic_long_xchg()

atomic_long_xchg() is not correctly defined for 32bit arches.

Signed-off-by: Eric Dumazet <[e-mail]>
Cc: Mathieu Desnoyers <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/asm-generic/atomic.h

···
 #define atomic_long_cmpxchg(l, old, new) \
 	(atomic_cmpxchg((atomic_t *)(l), (old), (new)))
 #define atomic_long_xchg(v, new) \
-	(atomic_xchg((atomic_t *)(l), (new)))
+	(atomic_xchg((atomic_t *)(v), (new)))
 
 #endif  /*  BITS_PER_LONG == 64  */