krb5: add prototype to silence clang warnings on mvsnprintf()
"error: format string is not a string literal"
Follow-up to 09230127589eccc7 which made the warning appear
Assisted-by: Viktor Szakats
Closes #12803
diff --git a/lib/krb5.c b/lib/krb5.c
index b334ae2..4db19fb 100644
--- a/lib/krb5.c
+++ b/lib/krb5.c
@@ -435,6 +435,9 @@
/* Send an FTP command defined by |message| and the optional arguments. The
function returns the ftp_code. If an error occurs, -1 is returned. */
static int ftp_send_command(struct Curl_easy *data, const char *message, ...)
+ CURL_PRINTF(2, 3);
+
+static int ftp_send_command(struct Curl_easy *data, const char *message, ...)
{
int ftp_code;
ssize_t nread = 0;
