Add -P option to help menu

ser2sock.c

@@ -410,7 +410,7 @@ void show_help(const char *appName)
  stderr,
  "Usage: %s -p <socket listen port> -s <serial port dev>\n\n"
  " -h, -help display this help and exit\n"
- " -f <config path> override config file path\n"
+ " -f <config path> override config file path and name\n"
  " -p port socket port to listen on\n"
  " -s <serial device> serial device; ex /dev/ttyUSB0\n"
  "options\n"
@@ -419,6 +419,7 @@ void show_help(const char *appName)
  " -d daemonize\n"
  " -0 raw device mode - no info messages\n"
  " -t send terminal init string\n"
+ " -P <pid pathname> override default PID file path and name\n"
  " -g debug level 0-3\n"
  " -c keep incoming connections when a serial device is disconnected\n"
  " -w milliseconds delay between attempts to open a serial device (5000)\n"