unmapping super devices: do not remove ramdisk mountpoints

Change-Id: Iabd543e914887af78813805141604ae0ca1c812d
diff --git a/partitionmanager.cpp b/partitionmanager.cpp
index a4d84ec..9f67730 100755
--- a/partitionmanager.cpp
+++ b/partitionmanager.cpp
@@ -3578,7 +3578,6 @@
 				LOGINFO("removing cow partition: %s\n", cow_partition.c_str());
 				destroyed = DestroyLogicalPartition(cow_partition);
 			}
-			rmdir((*iter)->Mount_Point.c_str());
 			iter = Partitions.erase(iter);
 			delete part;
 			if (!destroyed) {