librbd: fix rbd_features_to_string output

if features = 61, it will output ",deep-flattenexclusive-lockfast-difflayeringobject-map".
I think "deep-flatten,exclusive-lock,fast-diff,layering,object-map" is suitable output.

Signed-off-by: Zheng Yin <zhengyin@cmss.chinamobile.com>

diff --git a/src/librbd/Features.cc b/src/librbd/Features.cc
index 8623adb4ee343827fc1329a3484aaead952b589a..a2c25169c432b91bc0f2c4f541ea21666b5a70c5 100644 (file)
--- a/src/librbd/Features.cc
+++ b/src/librbd/Features.cc
@@ -34,8 +34,8 @@ std::string rbd_features_to_string(uint64_t features,
   std::string r;
   for (auto& i : RBD_FEATURE_MAP) {
     if (features & i.second) {
-      if (r.empty()) {
-       r += ",";
+      if (!r.empty()) {
+      r += ",";
       }
       r += i.first;
       features &= ~i.second;