api doc: clarify 'returns' of gsm48_mi_to_string()
Change-Id: I81646ff8284061a60c208bd8f9233f66c3e410f8
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index 17b0829..43b10b7 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -737,10 +737,12 @@
* \param[in] str_len Length of \a string in bytes
* \param[in] mi Mobile Identity to be stringified
* \param[in] mi_len Length of \a mi in bytes
- * \returns WARNING: the return value of this function is not well implemented.
+ * \returns Return <= 0 on error, > 0 on success.
+ * WARNING: the return value of this function is not well implemented.
* Depending on the MI type and amount of output buffer, this may return
* the nr of written bytes, or the written strlen(), or the snprintf()
- * style strlen()-if-the-buffer-were-large-enough. */
+ * style strlen()-if-the-buffer-were-large-enough.
+ */
int gsm48_mi_to_string(char *string, int str_len, const uint8_t *mi, int mi_len)
{
int rc;