build: import GetPersistentVolumeClass from component-helpers

Signed-off-by: Yonatan Kahana <yonatankahana.il@gmail.com>

vendor/github.com/prometheus/procfs/internal/util/parse.go

@@ -73,15 +73,6 @@ func ReadUintFromFile(path string) (uint64, error) {
 	return strconv.ParseUint(strings.TrimSpace(string(data)), 10, 64)
 }
 
-// ReadIntFromFile reads a file and attempts to parse a int64 from it.
-func ReadIntFromFile(path string) (int64, error) {
-	data, err := ioutil.ReadFile(path)
-	if err != nil {
-		return 0, err
-	}
-	return strconv.ParseInt(strings.TrimSpace(string(data)), 10, 64)
-}
-
 // ParseBool parses a string into a boolean pointer.
 func ParseBool(b string) *bool {
 	var truth bool