lrdp-v2: quiet down roareadiff

If a zillion billion differences are found in the RO area, just print to
the log once to notify the operator of that fact, instead of printing a
zillion billion times.

Change-Id: Ie61afe5b8bd2cb207f594b8ee46ebac1af95a08a

linux-ramdump-parser-v2/parsers/roareadiff.py

-# Copyright (c) 2013, The Linux Foundation. All rights reserved.
+# Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 and
@@ -53,6 +53,7 @@ class ROData(RamParser):
                 if not prgheader.flags & PF_W:
                     count = prgheader.vaddr
                     detect = 0
+                    printed_once = False
                     while count < prgheader.vaddr + prgheader.memsz:
                         fd.seek(prgheader.offset + (count - prgheader.vaddr))
                         ram_value = self.ramdump.read_word(count)
@@ -61,8 +62,10 @@ class ROData(RamParser):
                             break
 
                         if detect == 0 and vm_value != ram_value:
-                            print_out_str(
-                                'Differences found! Differences written to roareadiff.txt')
+                            if not printed_once:
+                                print_out_str(
+                                    'Differences found! Differences written to roareadiff.txt')
+                            printed_once = True
                             ddr_str = 'detect RO area differences between vmlinux and DDR at 0x{0:0>8x}\n'.format(
                                 count)
                             ddr_str += 'from DDR:\n'