[vte] ring: Tiny code cleanup: maintain GString integrity

[Egmont Koblinger <egmontkob src gnome org>]

commit ca7f577a8ff92804d087145a1efad3fb6be2fefc
Author: Egmont Koblinger <egmont gmail com>
Date:   Mon Apr 24 13:48:55 2017 +0200

    ring: Tiny code cleanup: maintain GString integrity

 src/ring.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/ring.cc b/src/ring.cc
index e090610..36d82e1 100644
--- a/src/ring.cc
+++ b/src/ring.cc
@@ -236,7 +236,7 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
        record = records[0];
 
        if (G_LIKELY (buffer->len && buffer->str[buffer->len - 1] == '\n'))
-               buffer->len--;
+                g_string_truncate (buffer, buffer->len - 1);
        else
                row->attr.soft_wrapped = TRUE;