TT#111150 Remove tautological test in dtmf_inject()

The tracker.most array is of unsigned char, so pt which gets
unconditionally assigned will always be >= 0.

Change-Id: I8adc06fc6c65aa0e33ef6614eb77c67b0dc07517
Warned-by: lgtm

daemon/dtmf.c

@@ -315,8 +315,6 @@ const char *dtmf_inject(struct call_media *media, int code, int volume, int dura
 		pt = ssrc_in->tracker.most[i];
 		if (pt == 255)
 			continue;
-		if (pt < 0)
-			break;
 
 		ch = codec_handler_get(media, pt);
 		if (!ch)