Remove some last traces of lowvsyslog that were missed; Add a SYSLOG emergency channel for handling assertion output more cleanly

drivers/usbdev/usbdev_trace.c

@@ -100,10 +100,10 @@ static int usbtrace_syslog(const char *fmt, ...)
   va_list ap;
   int ret;
 
-  /* Let lowvsyslog do the real work */
+  /* Let vsyslog do the real work */
 
   va_start(ap, fmt);
-  ret = lowvsyslog(LOG_INFO, fmt, ap);
+  ret = vsyslog(LOG_INFO, fmt, ap);
   va_end(ap);
   return ret;
 }