explicitely declare void function argg and static functions

clients/lcdvc/lcd_link.h

@@ -1,13 +1,13 @@
 #ifndef LCD_LINK_H
 #define LCD_LINK_H
 
-extern char * address;
+extern char *address;
 extern int port;
 
-int connect_and_setup();
-int read_response( char * str, int maxsize );
-int process_response( char * str );
-int update_display();
-int send_nop();
+int connect_and_setup(void);
+int read_response(char *str, int maxsize);
+int process_response(char *str);
+int update_display(void);
+int send_nop(void);
 
 #endif