make write() failures on Zap channels more prominent than 'debug' messages (bug #4107)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5531 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_zap.c

@@ -4391,8 +4391,7 @@ static int my_zt_write(struct zt_pvt *p, unsigned char *buf, int len, int index,
 			size = (linear ? READ_SIZE * 2 : READ_SIZE);
 		res = write(fd, buf, size);
 		if (res != size) {
-			if (option_debug)
-				ast_log(LOG_DEBUG, "Write returned %d (%s) on channel %d\n", res, strerror(errno), p->channel);
+			ast_log(LOG_WARNING, "Write returned %d (%s) on channel %d - audio may have been lost\n", res, strerror(errno), p->channel);
 			return sent;
 		}
 		len -= size;