mgcp_e1: fix log output

Its not the E1 timeslot that is updated, its the E1 line instead
(which includes the timeslot)

Change-Id: Ic72cf90ebdba1b5e395089417c6df5b962f8ffc8
diff --git a/src/libosmo-mgcp/mgcp_e1.c b/src/libosmo-mgcp/mgcp_e1.c
index 7f30c1d..24f297f 100644
--- a/src/libosmo-mgcp/mgcp_e1.c
+++ b/src/libosmo-mgcp/mgcp_e1.c
@@ -401,7 +401,7 @@
 	}
 	rc = e1inp_line_update(e1_line);
 	if (rc < 0) {
-		LOGPTRUNK(trunk, DE1, LOGL_ERROR, "failed to update E1 timeslot %u.\n", ts_nr);
+		LOGPTRUNK(trunk, DE1, LOGL_ERROR, "failed to update E1 line %u.\n", ts_nr);
 		return -EINVAL;
 	}