Added support for ext4 ASEC resizing.

ASECs formatted as ext4 can now be resized using vdc asec resize.
Refactored some common code.
Requires resize2fs.

Change-Id: Ie78bb6015114a7bc4af42b16d1f299322ffc1e2a
Signed-off-by: Daniel Rosenberg <drosen@google.com>
diff --git a/Devmapper.cpp b/Devmapper.cpp
index 6f43ac0..700e538 100644
--- a/Devmapper.cpp
+++ b/Devmapper.cpp
@@ -125,8 +125,8 @@
     io->flags = flags;
     if (name) {
         size_t ret = strlcpy(io->name, name, sizeof(io->name));
-	if (ret >= sizeof(io->name))
-		abort();
+        if (ret >= sizeof(io->name))
+            abort();
     }
 }