ethereum: fix typos in interfaces.go (ethereum#15149)

Author: wraith7

interfaces.go

@@ -102,7 +102,7 @@ type SyncProgress struct {
 	CurrentBlock  uint64 // Current block number where sync is at
 	HighestBlock  uint64 // Highest alleged block number in the chain
 	PulledStates  uint64 // Number of state trie entries already downloaded
-	KnownStates   uint64 // Total number os state trie entries known about
+	KnownStates   uint64 // Total number of state trie entries known about
 }
 
 // ChainSyncReader wraps access to the node's current sync status. If there's no
@@ -129,7 +129,7 @@ type ContractCaller interface {
 	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
 }
 
-// FilterQuery contains options for contact log filtering.
+// FilterQuery contains options for contract log filtering.
 type FilterQuery struct {
 	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
 	ToBlock   *big.Int         // end of the range, nil means latest block