Address PR comments

x/stake/keeper/keeper.go

@@ -11,6 +11,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/stake/types"
 )
 
+const aminoCacheSize = 500
+
 // keeper of the stake store
 type Keeper struct {
 	storeKey           sdk.StoreKey
@@ -34,7 +36,7 @@ func NewKeeper(cdc *codec.Codec, key, tkey sdk.StoreKey, ck bank.Keeper, paramst
 		bankKeeper:         ck,
 		paramstore:         paramstore.WithTypeTable(ParamTypeTable()),
 		hooks:              nil,
-		validatorCache:     make(map[string]cachedValidator, 500),
+		validatorCache:     make(map[string]cachedValidator, aminoCacheSize),
 		validatorCacheList: list.New(),
 		codespace:          codespace,
 	}

x/stake/keeper/validator.go

@@ -42,7 +42,7 @@ func (k Keeper) GetValidator(ctx sdk.Context, addr sdk.ValAddress) (validator ty
 	k.validatorCacheList.PushBack(cachedVal)
 
 	// if the cache is too big, pop off the last element from it
-	if k.validatorCacheList.Len() > 500 {
+	if k.validatorCacheList.Len() > aminoCacheSize {
 		valToRemove := k.validatorCacheList.Remove(k.validatorCacheList.Front()).(cachedValidator)
 		delete(k.validatorCache, valToRemove.marshalled)
 	}