Apply review nits to metadata helpers

Lower-case the doc comment on `metadataFromInternal` to match the
unexported function name, wrap it to ~80 columns, and terminate it
with a period. Replace `i -= 1` with `i--` in the
`MetadataFlattenFull` branch of `ExtractMetadata` to match the
incrementor style used in the loop body of the other branch.

Signed-off-by: Hidde Beydals <hidde@hhh.computer>

Author: hiddeco

stores/metadata.go

@@ -127,7 +127,7 @@ func ExtractMetadata(branches sops.TreeBranches, opts MetadataOpts) (sops.TreeBr
 						entry.Key = key[len(SopsPrefix):]
 						metadataTree = append(metadataTree, entry)
 						branch = append(branch[:i], branch[i+1:]...)
-						i -= 1
+						i--
 					}
 				}
 			}

stores/stores.go

@@ -114,7 +114,8 @@ type hckmskey struct {
 	EncryptedDataKey string `mapstructure:"enc"`
 }
 
-// MetadataFromInternal converts an internal SOPS metadata representation to a representation appropriate for storage
+// metadataFromInternal converts an internal SOPS metadata representation to a
+// representation appropriate for storage.
 func metadataFromInternal(sopsMetadata sops.Metadata) metadata {
 	var m metadata
 	m.LastModified = sopsMetadata.LastModified.Format(time.RFC3339)