fix comment and variable name typos

internal/archiver/archiver.go

@@ -162,7 +162,7 @@ func (o Options) ApplyDefaults() Options {
 	if o.SaveTreeConcurrency == 0 {
 		// can either wait for a file, wait for a tree, serialize a tree or wait for saveblob
 		// the last two are cpu-bound and thus mutually exclusive.
-		// Also allow waiting for FileReadConcurrency files, this is the maximum of files
+		// Also allow waiting for ReadConcurrency files, this is the maximum of files
 		// which currently can be in progress. The main backup loop blocks when trying to queue
 		// more files to read.
 		o.SaveTreeConcurrency = uint(runtime.GOMAXPROCS(0)) + o.ReadConcurrency

internal/archiver/exclude.go

@@ -214,7 +214,7 @@ func newDeviceMap(allowedSourcePaths []string, fs fs.FS) (deviceMap, error) {
 	return deviceMap, nil
 }
 
-// IsAllowed returns true if the path is located on an allowed device.
+// IsAllowed reports whether the path is located on an allowed device.
 func (m deviceMap) IsAllowed(item string, deviceID uint64, fs fs.FS) (bool, error) {
 	for dir := item; ; dir = fs.Dir(dir) {
 		debug.Log("item %v, test dir %v", item, dir)