UBUNTU: SAUCE: (no-up) kconfig: in debug mode some 0 length message prints occur

Has no real kernel impact, so continue to carry.

When we enable the zconfdump() debugging we see assertion failures
attempting to print the config.  Convert this into a noop.
Signed-off-by: Andy Whitcroft <apw@canonical.com>

scripts/kconfig/lkc.h

@@ -88,7 +88,9 @@ void set_all_choice_values(struct symbol *csym);
 /* confdata.c and expr.c */
 static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out)
 {
-	assert(len != 0);
+	//assert(len != 0);
+	if (len == 0)
+		return;
 
 	if (fwrite(str, len, count, out) != count)
 		fprintf(stderr, "Error in writing or end of file.\n");