After parsing information elements in IAX frames, set the data length to zero,

so that code later on does not think it has data to copy.
(ASA-2007-015)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@75440 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -6811,6 +6811,7 @@ static int socket_read(int *id, int fd, short events, void *cbdata)
 					return 1;
 				}
 				f.data = NULL;
+				f.datalen = 0;
 			} else
 				f.data = buf + sizeof(*fh);
 		} else {