refactor: replace deprecated functions

fs/fs.go

@@ -70,33 +70,3 @@ func FindBySubstring(dir, substring string) (k string, err error) {
 	err = errors.New("not found")
 	return
 }
-
-func FindKernel(files []os.FileInfo, kname string) (name string, err error) {
-	for _, file := range files {
-		if strings.HasPrefix(file.Name(), "vmlinuz") {
-			if strings.Contains(file.Name(), kname) {
-				name = file.Name()
-				return
-			}
-		}
-	}
-
-	err = errors.New("cannot find kernel")
-	return
-}
-
-func FindInitrd(files []os.FileInfo, kname string) (name string, err error) {
-	for _, file := range files {
-		if strings.HasPrefix(file.Name(), "initrd") ||
-			strings.HasPrefix(file.Name(), "initramfs") {
-
-			if strings.Contains(file.Name(), kname) {
-				name = file.Name()
-				return
-			}
-		}
-	}
-
-	err = errors.New("cannot find kernel")
-	return
-}