asm-generic/atomic.h: simplify inc/dec test helpers

We already declared inc/dec helpers, so we don't need to call the
atomic_{add,sub}_return funcs directly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arun Sharma <asharma@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/atomic.h

@@ -119,8 +119,8 @@ static inline void atomic_dec(atomic_t *v)
 #define atomic_inc_return(v)		atomic_add_return(1, (v))
 
 #define atomic_sub_and_test(i, v)	(atomic_sub_return((i), (v)) == 0)
-#define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
-#define atomic_inc_and_test(v)		(atomic_add_return(1, (v)) == 0)
+#define atomic_dec_and_test(v)		(atomic_dec_return(v) == 0)
+#define atomic_inc_and_test(v)		(atomic_inc_return(v) == 0)
 
 #define atomic_xchg(ptr, v)		(xchg(&(ptr)->counter, (v)))
 #define atomic_cmpxchg(v, old, new)	(cmpxchg(&((v)->counter), (old), (new)))