Fix LP Bug#885696 two issues with checked_iter

 The error message raised by IOError needed %locals() added

 If there is no cache in the pipeline image_meta['size'] appears to be of
 type str on my system. Thus the compare of expected_size and bytes_written
 always failed even when the values should have matched.
 Unconditionally convert expected_size to int to resolve this.
 Curiously image_meta['size'] is of type int if the cache is in the pipeline.
 This latter fix could be removed if the typing is resolved

Change-Id: I05eadce2b5ceb8eb7939acb41668aff089270e21

glance/api/v1/images.py

@@ -674,10 +674,11 @@ def checked_iter(image_id, expected_size, image_iter):
                         "bytes") % locals()
                 logger.error(msg)
                 raise IOError(errno.EPIPE, _("Corrupt image download for "
-                                             "image %(image_id)s"))
+                                             "image %(image_id)s") % locals())
 
         image_iter = result['image_iterator']
-        expected_size = image_meta['size']
+        # image_meta['size'] is a str
+        expected_size = int(image_meta['size'])
         response.app_iter = checked_iter(image_id, expected_size, image_iter)
         # Using app_iter blanks content-length, so we set it here...
         response.headers['Content-Length'] = image_meta['size']