backuptool: Preserve symlinks

Without -d, we copy the file sysmlinked rather than the symlink.

Change-Id: Ie0fdd43f29e53334464188c846dd7a3b7bb770cc
diff --git a/prebuilt/common/bin/backuptool.functions b/prebuilt/common/bin/backuptool.functions
index ff599f1..b3610e7 100644
--- a/prebuilt/common/bin/backuptool.functions
+++ b/prebuilt/common/bin/backuptool.functions
@@ -14,7 +14,7 @@
       echo "Skipping odexed apk $1"
     else
       mkdir -p "$C/$D"
-      cp -p "$1" "$C/$D/$F"
+      cp -dp "$1" "$C/$D/$F"
       if [ $DEBUG -eq 1 ]; then 
         echo backup_file "$1" "$C/$D/$F"
       fi
@@ -29,7 +29,7 @@
     if [ ! -d "$DIR" ]; then
       mkdir -p "$DIR"
     fi
-    cp -p "$C/$DIR/$FILE" "$1"
+    cp -dp "$C/$DIR/$FILE" "$1"
     if [ $DEBUG -eq 1 ]; then 
       echo restore_file "$C/$DIR/$FILE" "$1"
     fi