Remove dead code in Staking (#3559)

* Remove some dead code from staking

* Fix var name.

substrate/srml/staking/src/lib.rs

@@ -1001,8 +1001,8 @@ impl<T: Trait> Module<T> {
 
 	/// The total balance that can be slashed from a validator controller account as of
 	/// right now.
-	pub fn slashable_balance(who: &T::AccountId) -> BalanceOf<T> {
-		Self::stakers(who).total
+	pub fn slashable_balance_of(stash: &T::AccountId) -> BalanceOf<T> {
+		Self::bonded(stash).and_then(Self::ledger).map(|l| l.active).unwrap_or_default()
 	}
 
 	// MUTABLES (DANGEROUS)
@@ -1231,10 +1231,6 @@ impl<T: Trait> Module<T> {
 		maybe_new_validators
 	}
 
-	fn slashable_balance_of(stash: &T::AccountId) -> BalanceOf<T> {
-		Self::bonded(stash).and_then(Self::ledger).map(|l| l.active).unwrap_or_default()
-	}
-
 	/// Select a new validator set from the assembled stakers and their role preferences.
 	///
 	/// Returns the new `SlotStake` value and a set of newly selected _stash_ IDs.