chore: update IAVL (backport cosmos#14830) (cosmos#14835)

Co-authored-by: Marko <marbar3778@yahoo.com>

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/cosmos/cosmos-proto v1.0.0-alpha7
 	github.com/cosmos/cosmos-sdk/db v1.0.0-beta.1
 	github.com/cosmos/go-bip39 v1.0.0
-	github.com/cosmos/iavl v0.19.4
+	github.com/cosmos/iavl v0.19.5-rc.1
 	github.com/cosmos/ledger-cosmos-go v0.12.2
 	github.com/gogo/gateway v1.1.0
 	github.com/gogo/protobuf v1.3.2

go.sum

@@ -240,8 +240,8 @@ github.com/cosmos/go-bip39 v1.0.0 h1:pcomnQdrdH22njcAatO0yWojsUnCO3y2tNoV1cb6hHY
 github.com/cosmos/go-bip39 v1.0.0/go.mod h1:RNJv0H/pOIVgxw6KS7QeX2a0Uo0aKUlfhZ4xuwvCdJw=
 github.com/cosmos/gorocksdb v1.2.0 h1:d0l3jJG8M4hBouIZq0mDUHZ+zjOx044J3nGRskwTb4Y=
 github.com/cosmos/gorocksdb v1.2.0/go.mod h1:aaKvKItm514hKfNJpUJXnnOWeBnk2GL4+Qw9NHizILw=
-github.com/cosmos/iavl v0.19.4 h1:t82sN+Y0WeqxDLJRSpNd8YFX5URIrT+p8n6oJbJ2Dok=
-github.com/cosmos/iavl v0.19.4/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
+github.com/cosmos/iavl v0.19.5-rc.1 h1:4PjF2PdScyPbN1WbXpiQU21YtyonnrMU31xN74g8Rkg=
+github.com/cosmos/iavl v0.19.5-rc.1/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
 github.com/cosmos/keyring v1.1.7-0.20210622111912-ef00f8ac3d76 h1:DdzS1m6o/pCqeZ8VOAit/gyATedRgjvkVI+UCrLpyuU=
 github.com/cosmos/keyring v1.1.7-0.20210622111912-ef00f8ac3d76/go.mod h1:0mkLWIoZuQ7uBoospo5Q9zIpqq6rYCPJDSUdeCJvPM8=
 github.com/cosmos/ledger-cosmos-go v0.12.2 h1:/XYaBlE2BJxtvpkHiBm97gFGSGmYGKunKyF3nNqAXZA=

store/iavl/store.go

@@ -273,7 +273,7 @@ func (st *Store) Export(version int64) (*iavl.Exporter, error) {
 	if !ok || tree == nil {
 		return nil, fmt.Errorf("iavl export failed: unable to fetch tree for version %v", version)
 	}
-	return tree.Export(), nil
+	return tree.Export()
 }
 
 // Import imports an IAVL tree at the given version, returning an iavl.Importer for importing.