bracket-spacing: Don't modify current line

bracket-spacing: Don't modify current line

In bracket-spacing.pl, the current $line is being modified in $data.
That, however, spoils that $data for another check.  Introduce new
$tmpdata variable that can be used for temporary modifications.  The
difference between $data and $line is that $data are as much cleaned as
possible from non-code blocks and these changes must be kept.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>