dtwm: Resolve format-overflow issues

cde/programs/dtwm/WmHelp.c

@@ -2060,7 +2060,7 @@ SaveHelpResources(
     char *wsName;
     char workspaces[MAXWMPATH+1];
 
-    char buffer[MAXWMPATH+1];
+    char buffer[MAXWMPATH + 1 + 1024];
     char *res_class;
     char *data;
     int cum_len;

cde/programs/dtwm/WmInitWs.c

@@ -2209,8 +2209,8 @@ void
 InitWmDisplayEnv (void)
 {
     char *pDisplayName;
-    char buffer[256];
     char displayName[256];
+    char buffer[10 + sizeof(displayName)];
 
     pDisplayName = DisplayString (DISPLAY);