typo fix for lengh to length

pkg/storage/storage.go

@@ -163,7 +163,7 @@ func (s *Storage) History(name string) ([]*rspb.Release, error) {
 	return s.Driver.Query(map[string]string{"NAME": name, "OWNER": "TILLER"})
 }
 
-// removeLeastRecent removes items from history until the lengh number of releases
+// removeLeastRecent removes items from history until the length number of releases
 // does not exceed max.
 //
 // We allow max to be set explicitly so that calling functions can "make space"