WUtil: Marked args as unused for compiler in a callback functions

As callback have a fixed prototype, it can be correct to not use all the
arguments, so this patch adds the appropriate stuff to avoid a false
report from compiler.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

WINGs/menuparser_macros.c

@@ -679,6 +679,9 @@ static void mpm_get_user_name(WParserMacro *this, WMenuParser parser)
 /* Number id of the user under which we are running */
 static void mpm_get_user_id(WParserMacro *this, WMenuParser parser)
 {
+	/* Parameter not used, but tell the compiler that it is ok */
+	(void) parser;
+
 	if (this->value[0] != '\0') return; // Already evaluated, re-use previous
 	snprintf((char *) this->value, sizeof(this->value), "%d", getuid() );
 }

WINGs/proplist.c

@@ -1766,6 +1766,10 @@ int wmkdirhier(const char *path)
 static int wrmdirhier_fn(const char *path, const struct stat *st,
     int type, struct FTW *ftw)
 {
+	/* Parameter not used, but tell the compiler that it is ok */
+	(void) st;
+	(void) ftw;
+
 	switch(type) {
 	case FTW_D:
 		break;

WINGs/userdefaults.c

@@ -136,6 +136,9 @@ static void synchronizeUserDefaults(void *foo)
 {
 	UserDefaults *database = sharedUserDefaults;
 
+	/* Parameter not used, but tell the compiler that it is ok */
+	(void) foo;
+
 	while (database) {
 		if (!database->dontSync)
 			WMSynchronizeUserDefaults(database);