six locks: Simplify six_lock_counts()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/six.c

@@ -830,19 +830,12 @@ struct six_lock_count six_lock_counts(struct six_lock *lock)
 {
 	struct six_lock_count ret;
 
-	ret.n[SIX_LOCK_read]	= 0;
+	ret.n[SIX_LOCK_read]	= !lock->readers
+		? lock->state.read_lock
+		: pcpu_read_count(lock);
 	ret.n[SIX_LOCK_intent]	= lock->state.intent_lock + lock->intent_lock_recurse;
 	ret.n[SIX_LOCK_write]	= lock->state.seq & 1;
 
-	if (!lock->readers)
-		ret.n[SIX_LOCK_read] += lock->state.read_lock;
-	else {
-		int cpu;
-
-		for_each_possible_cpu(cpu)
-			ret.n[SIX_LOCK_read] += *per_cpu_ptr(lock->readers, cpu);
-	}
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(six_lock_counts);