Adding support for a different ubuntu series, like quantal

Signed-off-by: Ricardo Salveti de Araujo <ricardo.salveti@linaro.org>
diff --git a/build_images.py b/build_images.py
index d3d7ee0..34a4afc 100755
--- a/build_images.py
+++ b/build_images.py
@@ -100,10 +100,10 @@
                     delta_min, delta_secs)
     return '%s.gz' % imgfile
 
-def zsync_image(imgfile):
+def zsync_image(platform, imgfile):
     print "INFO: making zsync file for %s" % imgfile
     before = time.time()
-    basepath="http://snapshots.linaro.org/precise/pre-built"
+    basepath = "http://snapshots.linaro.org/%s/pre-built" % platform
     imgpath=os.sep.join(imgfile.split(os.sep)[-3:])
     zurl=basepath + os.sep + imgpath
     args = ('zsyncmake', '-b 2048', '-u', zurl, '-o', '%s.zsync' % imgfile,
@@ -315,7 +315,7 @@
                 rfsf = download(dm, binaryf[binary])
                 build_image(lmc, imgfile, hwpack, hwpf, binary, rfsf)
                 gzfile = compress_image(imgfile)
-                zsync_image(gzfile)
+                zsync_image(args.platform, gzfile)
                 create_image_info(infofile, gzfile,
                                 imgfile, url, binaryf[binary])