Extend vold support for creating ext4 images.

Augment the Ext4::format function to take
a mountpoint parameter. This will then
be passed to make_ext4fs through the
-a option to allow proper security labeling.

Change-Id: Ic26703406a2c463c12e32c8103a0c75c727b7d29
diff --git a/Ext4.h b/Ext4.h
index a09b576..c5ab78a 100644
--- a/Ext4.h
+++ b/Ext4.h
@@ -23,7 +23,7 @@
 public:
     static int doMount(const char *fsPath, const char *mountPoint, bool ro, bool remount,
             bool executable);
-    static int format(const char *fsPath);
+    static int format(const char *fsPath, const char *mountpoint);
 };
 
 #endif