Remove two compilation warnings (unused variables).

modules/access_filter/dump.c

@@ -325,6 +325,7 @@ static int KeyHandler (vlc_object_t *obj, char const *varname,
 {
     access_t *access = data;
 
+    (void)varname;
     (void)oldval;
     (void)obj;
 

modules/access_filter/record.c

@@ -264,6 +264,7 @@ static int EventKey( vlc_object_t *p_this, char const *psz_var,
     access_t     *p_access = p_data;
     access_sys_t *p_sys = p_access->p_sys;
 
+    (void)p_this;
     (void)psz_var;
     (void)oldval;