Fixing a lot of string formatting issues with regards to:

* Improper format specifier (e.g. %s for bools or %s for ints)
  * More or less parameters than format specifiers
  * Not calling a formatting function when it should have (e.g. Error() instead of Errorf())

pkg/kubectl/cmd/label.go

@@ -110,7 +110,7 @@ func parseLabels(spec []string) (map[string]string, []string, error) {
 		} else if strings.HasSuffix(labelSpec, "-") {
 			remove = append(remove, labelSpec[:len(labelSpec)-1])
 		} else {
-			return nil, nil, fmt.Errorf("unknown label spec: %v")
+			return nil, nil, fmt.Errorf("unknown label spec: %v", labelSpec)
 		}
 	}
 	for _, removeLabel := range remove {