Fix mkyaffs2image extra flags in the release tools.

Change-Id: I806e3e85ef89941edf04352331e25730c491c470
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 037c4cf..6bb37ae 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -36,6 +36,7 @@
 OPTIONS.tempfiles = []
 OPTIONS.device_specific = None
 OPTIONS.extras = {}
+OPTIONS.mkyaffs2_extra_flags = None
 
 
 # Values for "certificate" in apkcerts that mean special things.
@@ -69,6 +70,17 @@
       pass
 
 
+def LoadMkyaffs2ExtraFlags():
+  """Load mkyaffs2 extra flags."""
+  try:
+    fn = os.path.join(OPTIONS.input_tmp, "META", "mkyaffs2-extra-flags.txt");
+    if os.access(fn, os.F_OK):
+      OPTIONS.mkyaffs2_extra_flags = open(fn).read().rstrip("\n")
+  except IOError, e:
+    if e.errno == errno.ENOENT:
+      pass
+
+
 def BuildAndAddBootableImage(sourcedir, targetname, output_zip):
   """Take a kernel, cmdline, and ramdisk directory from the input (in
   'sourcedir'), and turn them into a boot image.  Put the boot image