isofs "default NLS charset not used" fix

Hello again,

Since nobody has made any suggestions about the behaviour mentioned above being a feature and not a bug, I took a liberty to fix it - if changing one constant in one line of C code can be called "fixing".

The attached diff has been made against vanilla 2.6.5 kernel sources. A bit of context changing will be in order for it to apply to 2.4.26 because of filesystem options structure type having changed; I haven't looked at 2.2.

Regards,

MS

@@ -794,7 +794,7 @@
 
 #ifdef CONFIG_JOLIET
 	if (joliet_level && opt.utf8 == 0) {
-		char * p = opt.iocharset ? opt.iocharset : "iso8859-1";
+		char * p = opt.iocharset ? opt.iocharset : CONFIG_NLS_DEFAULT;
 		sbi->s_nls_iocharset = load_nls(p);
 		if (! sbi->s_nls_iocharset) {
 			/* Fail only if explicit charset specified */