locking/atomic, arch/m68k: Remove comment

I misread the inline asm. It uses a rare construct to provide an input
to a previously declared output to do the atomic_read().
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

arch/m68k/include/asm/atomic.h

@@ -38,13 +38,6 @@ static inline void atomic_##op(int i, atomic_t *v)			\
 
 #ifdef CONFIG_RMW_INSNS
 
-/*
- * Am I reading these CAS loops right in that %2 is the old value and the first
- * iteration uses an uninitialized value?
- *
- * Would it not make sense to add: tmp = atomic_read(v); to avoid this?
- */
-
 #define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
 static inline int atomic_##op##_return(int i, atomic_t *v)		\
 {									\