Fix test script for proper output.

--- ./t/djbish.plx
+++ ./t/djbish.plx
@@ -10,5 +10,5 @@ close SOUT
   or die "cannot close fd 1 - $!";
 
 chomp $read;
-exit 20 if $read eq "#!perl -w"; # the top line of this file
+exit 20 if $read eq "#!/usr/bin/perl -w"; # the top line of this file
 exit 1;