netfilter: bitwise: replace gotos with returns.

When dumping a bitwise expression, if any of the puts fails, we use goto
to jump to a label.  However, no clean-up is required and the only
statement at the label is a return.  Drop the goto's and return
immediately instead.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>