fix a typo

Signed-off-by: hujun5 <hujun5@xiaomi.com>

Author: hujun260

netutils/chat/chat.c

@@ -61,7 +61,7 @@
 #define CHAT_TOKEN_SIZE    128
 
 /****************************************************************************
- * Pivate types
+ * Private types
  ****************************************************************************/
 
 /* Type of singly-linked list of tokens */