input/ipaccess: Fix segv caused by use of uninitialized var

This is a regression coming from the recent split of the
handle_ts1_read method in two.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Holger Hans Peter Freyther <zecke@selfish.org>
diff --git a/openbsc/src/input/ipaccess.c b/openbsc/src/input/ipaccess.c
index 8a22810..40891ae 100644
--- a/openbsc/src/input/ipaccess.c
+++ b/openbsc/src/input/ipaccess.c
@@ -319,7 +319,7 @@
 		return error;
 	}
 
-	DEBUGP(DMI, "RX %u: %s\n", ts_nr, hexdump(msgb_l2(msg), ret));
+	DEBUGP(DMI, "RX %u: %s\n", ts_nr, hexdump(msgb_l2(msg), msgb_l2len(msg)));
 
 	hh = (struct ipaccess_head *) msg->data;
 	if (hh->proto == IPAC_PROTO_IPACCESS) {