Fix strict prototype warnings

Author: nikic

apc.h

@@ -124,7 +124,7 @@ PHP_APCU_API int _apc_register_serializer(
 
 /* {{{ apc_get_serializers
  fetches the list of serializers */
-PHP_APCU_API apc_serializer_t* apc_get_serializers(); /* }}} */
+PHP_APCU_API apc_serializer_t* apc_get_serializers(void); /* }}} */
 
 /* {{{ apc_find_serializer
  finds a previously registered serializer by name */

apc_lock.h

@@ -72,8 +72,8 @@ typedef apc_windows_cs_rwlock_t apc_lock_t;
 	apc_lock_cleanup destroys those attributes
   This saves us from having to create and destroy attributes for
   every lock we use at runtime */
-PHP_APCU_API zend_bool apc_lock_init();
-PHP_APCU_API void      apc_lock_cleanup();
+PHP_APCU_API zend_bool apc_lock_init(void);
+PHP_APCU_API void      apc_lock_cleanup(void);
 /*
   The following functions should be self explanitory:
 */

apc_mutex.h

@@ -27,8 +27,8 @@
 
 typedef pthread_mutex_t apc_mutex_t;
 
-PHP_APCU_API zend_bool apc_mutex_init();
-PHP_APCU_API void apc_mutex_cleanup();
+PHP_APCU_API zend_bool apc_mutex_init(void);
+PHP_APCU_API void apc_mutex_cleanup(void);
 PHP_APCU_API zend_bool apc_mutex_create(apc_mutex_t *lock);
 PHP_APCU_API zend_bool apc_mutex_lock(apc_mutex_t *lock);
 PHP_APCU_API zend_bool apc_mutex_unlock(apc_mutex_t *lock);

apc_signal.h

@@ -34,8 +34,8 @@ typedef struct apc_signal_info_t {
 	apc_signal_entry_t **prev;      /* Previous signal handlers */
 } apc_signal_info_t;
 
-void apc_set_signals();
-void apc_shutdown_signals();
+void apc_set_signals(void);
+void apc_shutdown_signals(void);
 
 #endif