unicode: simplify utf8len

Just use the utf8nlen implementation with a (size_t)-1 len argument,
similar to utf8_lookup.  Also move the function to utf8-selftest.c, as
it isn't used anywhere else.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

fs/unicode/utf8-norm.c

@@ -391,36 +391,6 @@ static utf8leaf_t *utf8lookup(const struct utf8data *data,
 	return utf8nlookup(data, hangul, s, (size_t)-1);
 }
 
-/*
- * Length of the normalization of s.
- * Return -1 if s is not valid UTF-8 unicode.
- *
- * A string of Default_Ignorable_Code_Point has length 0.
- */
-ssize_t utf8len(const struct utf8data *data, const char *s)
-{
-	utf8leaf_t	*leaf;
-	size_t		ret = 0;
-	unsigned char	hangul[UTF8HANGULLEAF];
-
-	if (!data)
-		return -1;
-	while (*s) {
-		leaf = utf8lookup(data, hangul, s);
-		if (!leaf)
-			return -1;
-		if (utf8agetab[LEAF_GEN(leaf)] > data->maxage)
-			ret += utf8clen(s);
-		else if (LEAF_CCC(leaf) == DECOMPOSE)
-			ret += strlen(LEAF_STR(leaf));
-		else
-			ret += utf8clen(s);
-		s += utf8clen(s);
-	}
-	return ret;
-}
-EXPORT_SYMBOL(utf8len);
-
 /*
  * Length of the normalization of s, touch at most len bytes.
  * Return -1 if s is not valid UTF-8 unicode.

fs/unicode/utf8-selftest.c

@@ -160,6 +160,11 @@ static const struct {
 	}
 };
 
+static ssize_t utf8len(const struct utf8data *data, const char *s)
+{
+	return utf8nlen(data, s, (size_t)-1);
+}
+
 static void check_utf8_nfdi(void)
 {
 	int i;

fs/unicode/utf8n.h

@@ -39,7 +39,6 @@ extern const struct utf8data *utf8nfdicf(unsigned int maxage);
  * Returns 0 if only ignorable code points are present.
  * Returns -1 if the input is not valid UTF-8.
  */
-extern ssize_t utf8len(const struct utf8data *data, const char *s);
 extern ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len);
 
 /* Needed in struct utf8cursor below. */