confd: fix duplicate keystore log messages at boot

Only install the keys on CHANGE event, fixes this annoying issue:

Nov 5 01:32:10 ix confd[2011]: Installing HTTPS gencert certificate "self-signed"
Nov 5 01:32:10 ix confd[2011]: Installing SSH host key "genkey".
Nov 5 01:32:11 ix confd[2011]: Installing HTTPS gencert certificate "self-signed
Nov 5 01:32:11 ix confd[2011]: Installing SSH host key "genkey".

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

Author: troglobit

src/confd/src/keystore.c

@@ -313,8 +313,7 @@ int keystore_change(sr_session_ctx_t *session, struct lyd_node *config, struct l
 
 	switch (event) {
 	case SR_EV_UPDATE:
-		rc = keystore_update(session, config, diff);
-		break;
+		return keystore_update(session, config, diff);
 	case SR_EV_CHANGE:
 		if (diff && lydx_find_xpathf(diff, XPATH_KEYSTORE_SYM))
 			rc = interfaces_validate_keys(session, config);