am 918e5f9f: Better error code for unmounting not-mounted volumes

Merge commit '918e5f9f10b9c1ff929683743ffbf229027ce240' into gingerbread-plus-aosp

* commit '918e5f9f10b9c1ff929683743ffbf229027ce240':
  Better error code for unmounting not-mounted volumes

VolumeManager.cpp

@@ -559,7 +559,7 @@ int VolumeManager::unmountLoopImage(const char *id, const char *idHash,
         const char *fileName, const char *mountPoint, bool force) {
     if (!isMountpointMounted(mountPoint)) {
         SLOGE("Unmount request for %s when not mounted", id);
-        errno = EINVAL;
+        errno = ENOENT;
         return -1;
     }