classes/sanity: import regular expression module in SuSE distro check

We call re.sub here, so we need to "import re" or an error occurs
(tested on OpenSuSE 12.1).

(From OE-Core rev: cb1f7cffc171e6b182f33a69ff688d76b7f1baed)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/sanity.bbclass

@@ -124,6 +124,7 @@ def check_supported_distro(e):
         finally:
             f.close()
     elif os.path.exists("/etc/SuSE-release"):
+        import re
         f = open("/etc/SuSE-release", "r")
         try:
             distro = f.readline()