fix: reintroduce TopN state functions for keeper.go

Author: n2p5

x/ccv/provider/keeper/keeper.go

@@ -837,10 +837,10 @@ func (k Keeper) SetMinimumPowerInTopN(
 ) {
 	store := ctx.KVStore(k.storeKey)
 
-	powerBytes := make([]byte, 8)
-	binary.BigEndian.PutUint64(powerBytes, uint64(power))
+	buf := make([]byte, 8)
+	binary.BigEndian.PutUint64(buf, uint64(power))
 
-	store.Set(types.MinimumPowerInTopNKey(chainID), powerBytes)
+	store.Set(types.MinimumPowerInTopNKey(chainID), buf)
 }
 
 // GetMinimumPowerInTopN returns the minimum power required for a validator to be in the top N
@@ -850,12 +850,11 @@ func (k Keeper) GetMinimumPowerInTopN(
 	chainID string,
 ) (int64, bool) {
 	store := ctx.KVStore(k.storeKey)
-	bz := store.Get(types.MinimumPowerInTopNKey(chainID))
-	if bz == nil {
+	buf := store.Get(types.MinimumPowerInTopNKey(chainID))
+	if buf == nil {
 		return 0, false
 	}
-
-	return int64(binary.BigEndian.Uint64(bz)), true
+	return int64(binary.BigEndian.Uint64(buf)), true
 }
 
 // DeleteMinimumPowerInTopN removes the minimum power required for a validator to be in the top N