Remove usage of the pallet::getter macro from pallet-fast-unstake (#4514)

As per #3326, removes pallet::getter macro usage from
pallet-fast-unstake. The syntax `StorageItem::<T, I>::get()` should be
used instead.

cc @muraca

---------

Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>

prdoc/pr_4514.prdoc

+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Removed `pallet::getter` usage from pallet-fast-unstake
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      This PR removed the `pallet::getter`s from `pallet-fast-unstake`.
+      The syntax `StorageItem::<T, I>::get()` should be used instead.
+
+crates:
+  - name: pallet-fast-unstake
+    bump: major

substrate/frame/fast-unstake/src/lib.rs

@@ -141,7 +141,7 @@ macro_rules! log {
 	($level:tt, $patter:expr $(, $values:expr)* $(,)?) => {
 		log::$level!(
 			target: crate::LOG_TARGET,
-			concat!("[{:?}] 💨 ", $patter), <frame_system::Pallet<T>>::block_number() $(, $values)*
+			concat!("[{:?}] 💨 ", $patter), frame_system::Pallet::<T>::block_number() $(, $values)*
 		)
 	};
 }
@@ -227,7 +227,6 @@ pub mod pallet {
 	/// checked. The checking is represented by updating [`UnstakeRequest::checked`], which is
 	/// stored in [`Head`].
 	#[pallet::storage]
-	#[pallet::getter(fn eras_to_check_per_block)]
 	pub type ErasToCheckPerBlock<T: Config> = StorageValue<_, u32, ValueQuery>;
 
 	#[pallet::event]
@@ -332,7 +331,7 @@ pub mod pallet {
 		pub fn register_fast_unstake(origin: OriginFor<T>) -> DispatchResult {
 			let ctrl = ensure_signed(origin)?;
 
-			ensure!(ErasToCheckPerBlock::<T>::get() != 0, <Error<T>>::CallNotAllowed);
+			ensure!(ErasToCheckPerBlock::<T>::get() != 0, Error::<T>::CallNotAllowed);
 			let stash_account =
 				T::Staking::stash_by_ctrl(&ctrl).map_err(|_| Error::<T>::NotController)?;
 			ensure!(!Queue::<T>::contains_key(&stash_account), Error::<T>::AlreadyQueued);
@@ -373,7 +372,7 @@ pub mod pallet {
 		pub fn deregister(origin: OriginFor<T>) -> DispatchResult {
 			let ctrl = ensure_signed(origin)?;
 
-			ensure!(ErasToCheckPerBlock::<T>::get() != 0, <Error<T>>::CallNotAllowed);
+			ensure!(ErasToCheckPerBlock::<T>::get() != 0, Error::<T>::CallNotAllowed);
 
 			let stash_account =
 				T::Staking::stash_by_ctrl(&ctrl).map_err(|_| Error::<T>::NotController)?;