Fix wrong staking doc about transaction payment. (#6873)

* Fx #4616

* Fix #4616

frame/staking/src/lib.rs

@@ -606,7 +606,10 @@ pub struct Nominations<AccountId> {
 	///
 	/// Except for initial nominations which are considered submitted at era 0.
 	pub submitted_in: EraIndex,
-	/// Whether the nominations have been suppressed.
+	/// Whether the nominations have been suppressed. This can happen due to slashing of the
+	/// validators, or other events that might invalidate the nomination.
+	///
+	/// NOTE: this for future proofing and is thus far not used.
 	pub suppressed: bool,
 }
 
@@ -2444,8 +2447,9 @@ impl<T: Trait> Module<T> {
 		Ok(())
 	}
 
-	/// Update the ledger for a controller. This will also update the stash lock. The lock will
-	/// will lock the entire funds except paying for further transactions.
+	/// Update the ledger for a controller.
+	///
+	/// This will also update the stash lock.
 	fn update_ledger(
 		controller: &T::AccountId,
 		ledger: &StakingLedger<T::AccountId, BalanceOf<T>>