Remove unnecessary err != nil checks in the end of few functions (#1818)

Author: kirugan

blockchain/blockchain.go

@@ -461,11 +461,7 @@ func StoreBlockHeader(txn db.Transaction, header *core.Header) error {
 		return err
 	}
 
-	if err = txn.Set(db.BlockHeadersByNumber.Key(numBytes), headerBytes); err != nil {
-		return err
-	}
-
-	return nil
+	return txn.Set(db.BlockHeadersByNumber.Key(numBytes), headerBytes)
 }
 
 // blockHeaderByNumber retrieves a block header from database by its number

core/contract.go

@@ -164,11 +164,7 @@ func (c *ContractUpdater) UpdateStorage(diff map[felt.Felt]*felt.Felt, cb OnValu
 		}
 	}
 
-	if err = cStorage.Commit(); err != nil {
-		return err
-	}
-
-	return nil
+	return cStorage.Commit()
 }
 
 func ContractStorage(addr, key *felt.Felt, txn db.Transaction) (*felt.Felt, error) {