Add missing UNLOCK_CACHE in eet_open function.

Change-Id: I79db6bedf49c27499f3caa63d04dc6bb3ecfee60

SVN revision: 79290

src/lib/eet/eet_lib.c

@@ -1487,7 +1487,10 @@ open_error:
    else
      {
         if (mode != EET_FILE_MODE_WRITE)
-          return NULL;
+          {
+            UNLOCK_CACHE;
+            return NULL;
+          }
 
         size = 0;