USB: usbtmc: indent & braces disagree, something else is desired

It seems that there's rather involved way to say something
which is commonly written in a plain simple form.

Some type changes would probably be necessary to get gcc
to do bitops instead of divide but it's no worse after my
change than before I think.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>