tests: enable all go vet checks

...and fix reported errors:

internal/fusefrontend_reverse/rfile.go:40: github.com/rfjakob/gocryptfs/internal/contentenc.FileHeader composite literal uses unkeyed fields
internal/fusefrontend_reverse/rfs.go:249: github.com/hanwen/go-fuse/fuse.DirEntry composite literal uses unkeyed fields
internal/fusefrontend_reverse/rfs.go:264: github.com/hanwen/go-fuse/fuse.DirEntry composite literal uses unkeyed fields

internal/fusefrontend_reverse/rfile.go

@@ -34,10 +34,14 @@ func (rfs *reverseFS) NewFile(relPath string, flags uint32) (nodefs.File, fuse.S
 		return nil, fuse.ToStatus(err)
 	}
 	id := derivePathIV(relPath)
+	header := contentenc.FileHeader{
+		Version: contentenc.CurrentVersion,
+		Id:      id,
+	}
 	return &reverseFile{
 		File:       nodefs.NewDefaultFile(),
 		fd:         fd,
-		header:     contentenc.FileHeader{contentenc.CurrentVersion, id},
+		header:     header,
 		contentEnc: rfs.contentEnc,
 	}, fuse.OK
 }

internal/fusefrontend_reverse/rfs.go

@@ -246,7 +246,10 @@ func (rfs *reverseFS) OpenDir(cipherPath string, context *fuse.Context) ([]fuse.
 	// plus one for gocryptfs.diriv.
 	virtualFiles := make([]fuse.DirEntry, len(entries)+1)
 	// Virtual gocryptfs.diriv file
-	virtualFiles[0] = fuse.DirEntry{syscall.S_IFREG | 0400, nametransform.DirIVFilename}
+	virtualFiles[0] = fuse.DirEntry{
+		Mode: syscall.S_IFREG | 0400,
+		Name: nametransform.DirIVFilename,
+	}
 	// Actually used entries
 	nVirtual := 1
 
@@ -261,7 +264,10 @@ func (rfs *reverseFS) OpenDir(cipherPath string, context *fuse.Context) ([]fuse.
 			cName = rfs.nameTransform.EncryptName(entries[i].Name, dirIV)
 			if len(cName) > syscall.NAME_MAX {
 				cName = nametransform.HashLongName(cName)
-				dotNameFile := fuse.DirEntry{syscall.S_IFREG | 0600, cName + nametransform.LongNameSuffix}
+				dotNameFile := fuse.DirEntry{
+					Mode: syscall.S_IFREG | 0600,
+					Name: cName + nametransform.LongNameSuffix,
+				}
 				virtualFiles[nVirtual] = dotNameFile
 				nVirtual++
 			}

test.bash

@@ -13,4 +13,4 @@ go test ./... $*
 # The tests cannot to this themselves as they are run in parallel
 rm -Rf --one-file-system /tmp/gocryptfs-test-parent
 
-go tool vet -shadow=true .
+go tool vet -all -shadow .