[gnome-commander/ConvertWarningsToErrors] Fixes gcc warning about sign-compare

[Uwe Scholz <uwescholz src gnome org>]

commit c16aecfeed5d2e58ecdc1b2920ce30f3137a4451
Author: Uwe Scholz <uwescholz src gnome org>
Date:   Sat Apr 22 18:23:32 2017 +0200

    Fixes gcc warning about sign-compare

 src/gnome-cmd-file-list.cc |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/src/gnome-cmd-file-list.cc b/src/gnome-cmd-file-list.cc
index 5951288..934ac09 100644
--- a/src/gnome-cmd-file-list.cc
+++ b/src/gnome-cmd-file-list.cc
@@ -541,12 +541,13 @@ void GnomeCmdFileList::toggle_file(GnomeCmdFile *f)
     if (row == -1)
         return;
 
-    if (row < priv->visible_files.size())
+    guint real_row = row;
+    if (real_row < priv->visible_files.size())
     {
         if (!priv->selected_files.contain(f))
-            select_file(f, row);
+            select_file(f, real_row);
         else
-            unselect_file(f, row);
+            unselect_file(f, real_row);
     }
 }