Close the DAHDI FD on error when processing chan_dahdi toneduration config parameter.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@274579 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_dahdi.c

@@ -12175,6 +12175,7 @@ static int process_dahdi(struct dahdi_chan_conf *confp, const char *cat, struct
 					res = ioctl(ctlfd, DAHDI_SET_DIALPARAMS, &dps);
 					if (res < 0) {
 						ast_log(LOG_ERROR, "Invalid tone duration: %d ms: %s\n", toneduration, strerror(errno));
+						close(ctlfd);
 						return -1;
 					}
 				}