recovery: Fix the configuration of default_backup_format

I believe that this was missed (and therefore broken) in this commit:

commit a46e1bd7
Author: philz-cwm6 <phytowardt@gmail.com>
Date:   Sun Dec 1 22:26:45 2013 +0100

    Define paths for recovery settings files in a separate header

    Also, use get_primary_storage_path() to define the locations of .no_conf
    .many_confirm, and .hidenandroidprogress instead of hard-coding /sdcard/

    Change-Id: I50442a226af1d102786c833c0b53c25bf63c67a6
    (cherry picked from commit bd0fe453)

Conflicts:
	nandroid.c

Change-Id: I7e6541071b35f0725accabd9cb6cc27b3f7d0a57