Fix [-Wstrict-prototypes] in PCNTL extension .c files

Author: Girgias

ext/pcntl/pcntl.c

@@ -89,7 +89,7 @@ static void pcntl_siginfo_to_zval(int, siginfo_t*, zval*);
 #else
 static void pcntl_signal_handler(int);
 #endif
-static void pcntl_signal_dispatch();
+static void pcntl_signal_dispatch(void);
 static void pcntl_interrupt_function(zend_execute_data *execute_data);
 
 void php_register_signal_constants(INIT_FUNC_ARGS)