Fixed Environment variable reference

scripts/generator.pl

diff --git a/scripts/generator.pl b/scripts/generator.pl
index bcbc6fa..f9fed81 100644
--- a/scripts/generator.pl
+++ b/scripts/generator.pl
@@ -68,7 +68,7 @@
   my $name=""; $name=$1 if($mag=~m/([\w\-\.]+)\.mag$/);
   next unless(-f $cell);
   next unless(-f $lib);
-  next unless(-f "$CARAVEL/cells/mag/$name.mag");
+  next unless(-f $ENV{'$CARAVEL'}."/cells/mag/$name.mag");
 
   open CELL,"<$cell";
   print "$name $name(\n";