nostrdb: bolt11: move utf8_check into local function.

It isn't actually in the CCAN module (though it probably should be!).
So it breaks when we update.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: William Casarin <jb55@jb55.com>

nostrdb/src/bolt11/bolt11.c

@@ -178,6 +178,24 @@ static void decode_p(struct bolt11 *b11,
     *have_p = true;
 }
 
+/* Check for valid UTF-8 */
+static bool utf8_check(const void *vbuf, size_t buflen)
+{
+	const u8 *buf = vbuf;
+	struct utf8_state utf8_state = UTF8_STATE_INIT;
+	bool need_more = false;
+
+	for (size_t i = 0; i < buflen; i++) {
+		if (!utf8_decode(&utf8_state, buf[i])) {
+			need_more = true;
+			continue;
+		}
+		need_more = false;
+		if (errno != 0)
+			return false;
+	}
+	return !need_more;
+}
 
 static char *utf8_str(const tal_t *ctx, const u8 *buf TAKES, size_t buflen)
 {

nostrdb/src/bolt11/utf8.h

@@ -52,6 +52,4 @@ bool utf8_decode(struct utf8_state *utf8_state, char c);
  */
 size_t utf8_encode(uint32_t point, char dest[UTF8_MAX_LEN]);
 
-/* Check for valid UTF-8 */
-bool utf8_check(const void *vbuf, size_t buflen);
 #endif /* CCAN_UTF8_H */

nostrdb/src/util.h

@@ -28,6 +28,5 @@ static inline char *strdupn(const char *src, size_t size) {
 	dest[size] = '\0';
 	return dest;
 }
-
 #endif // NDB_UTIL_H