fix incorrect return value for fwide function

when the orientation of the stream was already set, fwide was
incorrectly returning its argument (the requested orientation) rather
than the actual orientation of the stream.

src/stdio/fwide.c

@@ -7,7 +7,8 @@
 int fwide(FILE *f, int mode)
 {
 	FLOCK(f);
-	if (!f->mode) mode = f->mode = NORMALIZE(mode);
+	if (!f->mode) f->mode = NORMALIZE(mode);
+	mode = f->mode;
 	FUNLOCK(f);
 	return mode;
 }