bankd/client: Fix memory leak if rspro_enc_msg() fails

Change-Id: Ib72b077d82939be0627b9dd7c905fb2a33db9ca5
diff --git a/src/bankd_main.c b/src/bankd_main.c
index cb78718..b3a5513 100644
--- a/src/bankd_main.c
+++ b/src/bankd_main.c
@@ -435,6 +435,7 @@
 	int rc;
 
 	if (!msg) {
+		ASN_STRUCT_FREE(asn_DEF_RsproPDU, pdu);
 		LOGW(worker, "error encoding RSPRO\n");
 		return -1;
 	}