Fix: possible memory leak in otrl_message_sending

Make sure we free the old messagep value if the fragment_and_send call
successfully sets it to a new value.

(Repairs a problem introduced in c87b3fe6

)

Fixes #25
Reported-by: b42 <b42@srck.net>
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Signed-off-by: Ian Goldberg <iang@cs.uwaterloo.ca>

src/message.c

@@ -441,8 +441,15 @@ fragment:
 	/* Fragment and send according to policy */
 	if (!err && messagep && *messagep) {
 	    if (context) {
+		char *rmessagep = NULL;
 		err = fragment_and_send(ops, opdata, context, *messagep,
-			fragPolicy, messagep);
+					fragPolicy, &rmessagep);
+		if (rmessagep) {
+		    /* Free the current message pointer and return back the
+		     * returned fragmented one. */
+		    free(*messagep);
+		    *messagep = rmessagep;
+		}
 	    }
 	}
 	return err;