dgnc: Remove redundant blank lines in dgnc_cls.c

There are a lot double of blank lines in dgnc_cls.c thus remove them to make
the file follow the CodingStyle. Also, remove one blank line at the
end of dgnc_cls.c.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>