vold2: Rename DeviceVolume -> DirectVolume

Signed-off-by: San Mehat <san@android.com>
diff --git a/Android.mk b/Android.mk
index 3af7544..07401e2 100644
--- a/Android.mk
+++ b/Android.mk
@@ -14,7 +14,7 @@
                   NetlinkHandler.cpp                   \
                   BlockDevice.cpp                      \
                   Volume.cpp                           \
-                  DeviceVolume.cpp      
+                  DirectVolume.cpp
 
 LOCAL_MODULE:= vold