frame_support::pallet_prelude: reexport StorageVersion (#11408)

* frame_support::pallet_prelude: reexport StorageVersion

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* cargo fmt

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

substrate/frame/contracts/src/lib.rs

@@ -114,7 +114,7 @@ use codec::{Encode, HasCompact};
 use frame_support::{
 	dispatch::Dispatchable,
 	ensure,
-	traits::{Contains, Currency, Get, Randomness, ReservableCurrency, StorageVersion, Time},
+	traits::{Contains, Currency, Get, Randomness, ReservableCurrency, Time},
 	weights::{DispatchClass, GetDispatchInfo, Pays, PostDispatchInfo, Weight},
 };
 use frame_system::{limits::BlockWeights, Pallet as System};
@@ -133,9 +133,6 @@ type TrieId = Vec<u8>;
 type BalanceOf<T> =
 	<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;
 
-/// The current storage version.
-const STORAGE_VERSION: StorageVersion = StorageVersion::new(7);
-
 /// Used as a sentinel value when reading and writing contract memory.
 ///
 /// It is usually used to signal `None` to a contract when only a primitive is allowed
@@ -222,6 +219,14 @@ pub mod pallet {
 	use frame_support::pallet_prelude::*;
 	use frame_system::pallet_prelude::*;
 
+	/// The current storage version.
+	const STORAGE_VERSION: StorageVersion = StorageVersion::new(7);
+
+	#[pallet::pallet]
+	#[pallet::storage_version(STORAGE_VERSION)]
+	#[pallet::without_storage_info]
+	pub struct Pallet<T>(PhantomData<T>);
+
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The time implementation used to supply timestamps to conntracts through `seal_now`.
@@ -353,11 +358,6 @@ pub mod pallet {
 		type AddressGenerator: AddressGenerator<Self>;
 	}
 
-	#[pallet::pallet]
-	#[pallet::storage_version(STORAGE_VERSION)]
-	#[pallet::without_storage_info]
-	pub struct Pallet<T>(PhantomData<T>);
-
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T>
 	where

substrate/frame/contracts/src/migration.rs

@@ -28,8 +28,6 @@ use sp_std::{marker::PhantomData, prelude::*};
 
 /// Wrapper for all migrations of this pallet, based on `StorageVersion`.
 pub fn migrate<T: Config>() -> Weight {
-	use frame_support::traits::StorageVersion;
-
 	let version = StorageVersion::get::<Pallet<T>>();
 	let mut weight: Weight = 0;