Fix typos in pkg

Signed-off-by: bin liu <liubin0329@gmail.com>

pkg/system/path.go

@@ -35,7 +35,7 @@ func DefaultPathEnv(os string) string {
 // This is used, for example, when validating a user provided path in docker cp.
 // If a drive letter is supplied, it must be the system drive. The drive letter
 // is always removed. Also, it translates it to OS semantics (IOW / to \). We
-// need the path in this syntax so that it can ultimately be contatenated with
+// need the path in this syntax so that it can ultimately be concatenated with
 // a Windows long-path which doesn't support drive-letters. Examples:
 // C:			--> Fail
 // C:\			--> \

pkg/tailfile/tailfile.go

@@ -16,7 +16,7 @@ var eol = []byte("\n")
 // ErrNonPositiveLinesNumber is an error returned if the lines number was negative.
 var ErrNonPositiveLinesNumber = errors.New("The number of lines to extract from the file must be positive")
 
-//TailFile returns last n lines of reader f (could be a fil).
+//TailFile returns last n lines of reader f (could be a nil).
 func TailFile(f io.ReadSeeker, n int) ([][]byte, error) {
 	if n <= 0 {
 		return nil, ErrNonPositiveLinesNumber