Static layout: Do not update PNOR when host is on

Static layout only has 1 active and functional PNOR. When host is
running, do not update PNOR.
This is done by checking the return value of freeSpace(), and if it
returns false, it means there is no space for PNOR because the host is
running and erase() returns false.

Tested: Verify the status becomes Failed when trying to activate a PNOR
        while host is running.

Change-Id: Ie2986b0c6fd29557685f67eb77ccc29709e1669a
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/item_updater.hpp b/item_updater.hpp
index 8b1bf0d..e27cccc 100644
--- a/item_updater.hpp
+++ b/item_updater.hpp
@@ -127,8 +127,10 @@
      *         needs to delete any PNOR version(s) it will delete the
      *         version(s) with the highest priority, skipping the
      *         functional PNOR version.
+     *
+     *  @return - Return if space is freed or not
      */
-    virtual void freeSpace() = 0;
+    virtual bool freeSpace() = 0;
 
     /** @brief Creates an active association to the
      *  newly active software image