doc a bit more

README.md

@@ -180,6 +180,7 @@ against checksum_url for a match/guess.
 In case a different hashing algorithm is in the filename of checksum_url
 it is recommended to explicitly set hashing algorithm instead; the
 outcome would be undetermined otherwise.
+Once go-getter is done with the file; it is deleted.
 
 The checksum query parameter is never sent to the backend protocol
 implementation. It is used at a higher level by go-getter itself.

checksum.go

@@ -139,7 +139,7 @@ func checksumsFromFile(checksumFile string, src *url.URL) (checkSums map[string]
 		return nil, fmt.Errorf(
 			"Error opening downloaded file: %s", err)
 	}
-	defer f.Close()
+	defer f.Close() // last defer comes first
 	rd := bufio.NewReader(f)
 	res := map[string]string{}
 	for {