Correct error code for CCC/SSL shutdown failure

include/curl/curl.h

@@ -397,8 +397,8 @@ typedef enum {
                                     generic so the error message will be of
                                     interest when this has happened */
 
-  CURLE_FTP_SSL_CCC_FAILED,      /* 80 - Failed to clear the FTP command
-                                    channel */
+  CURLE_SSL_SHUTDOWN_FAILED,     /* 80 - Failed to shut down the SSL
+                                    connection */
   CURL_LAST /* never use! */
 } CURLcode;