[gnome-commander/ConvertWarningsToErrors] src/utils.cc: fix for -Wswitch-default

[Uwe Scholz <uwescholz src gnome org>]

commit 5fd88fd682a4aceb10d0ba92ca768cf531f7d9c0
Author: Mamoru TASAKA <mtasaka fedoraproject org>
Date:   Sat Apr 29 01:43:08 2017 +0900

    src/utils.cc: fix for -Wswitch-default
    
    src/utils.cc:359:12: error: switch missing default case [-Werror=switch-default]
         switch (size_disp_mode)

 src/utils.cc |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/utils.cc b/src/utils.cc
index 4a96f6b..d207b75 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -405,6 +405,9 @@ const gchar *size2string (GnomeVFSFileSize size, GnomeCmdSizeDispMode size_disp_
         case GNOME_CMD_SIZE_DISP_MODE_PLAIN:
             g_snprintf (buf0, sizeof(buf0), "%lu ", size);
             break;
+
+        default:
+            break;
     }
 
     return buf0;