mk1mf.pl: replace chop to make it work in mixture of perls for Windows.

util/mk1mf.pl

@@ -347,7 +347,7 @@ open(IN,"<$infile") || die "unable to open $infile:$!\n";
 $_=<IN>;
 for (;;)
 	{
-	chop;
+	s/\s*$//; # was chop, didn't work in mixture of perls for Windows...
 
 	($key,$val)=/^([^=]+)=(.*)/;
 	if ($key eq "RELATIVE_DIRECTORY")